Patent Publication Number: US-10771402-B2

Title: Link aggregated fibre channel over ethernet system

Description:
BACKGROUND 
     The present disclosure relates generally to information handling systems, and more particularly to providing link level fault tolerance for Fibre Channel over Ethernet data traffic transmitted via Virtual Link Trunking (VLT) based link aggregated Fibre Channel Forwarding information handling systems. 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     Some information handling systems such as switches utilize link aggregation to combine multiple network connections in order to increase throughput, provide redundancy, and/or provide a variety of other link aggregation benefits known in the art. For example, some switches utilize Virtual Link Trunking (VLT), which is a proprietary link aggregation protocol that is provided by the Assignee of the present disclosure and that allows for the setup of an aggregated link to a plurality of different switches. VLT is a layer-2 link aggregation protocol that may be utilized by servers and access switches to, for example, provide a redundant load-balanced connection to the core-network in a loop-free environment, provide uplinks between access switches and core switches, and/or provide a variety of other VLT benefits that would be apparent to one of skill in the art. However, in network topologies utilizing Fibre Channel communications, the use of link aggregation raises some issues. 
     For example, network topologies utilizing Fibre Channel communications may include Fibre Channel switch devices such as, for example, Fiber Channel Forwarder (or Fibre Channel over Ethernet (FCoE) Forwarder) devices (FCF devices) that operate to transmit FCoE communications between Converged Network Adapters (CNAs) in host devices and the target devices with which they communicate. When multiple FCF devices are part of multi-switch Link Aggregation Groups (LAGs) such as those provided via VLT discussed above, conventional systems isolate the different FCF devices into two different network fabrics (e.g., by assigning each of the FCF devices different FCoE mapped address prefixes (FC-MAPs) and FCoE Virtual Local Area Networks (VLANs)). In such conventional systems, FCoE is only supported on individual FCF devices, as multiple FCFs operating as VLT peers are not capable of handling FCoE, and end-to-end path level redundancy (e.g., between the CNAs and the target devices) must be achieved using Multi-Path Input/Output (MPIO) on the host devices (as is done in “air-gapped” network fabrics.) As such, the FCF devices in such conventional systems act as independent Fibre Channel switches, with the link fault tolerance provided by LAGs (and/or link aggregation infrastructure provided by VLT) unused, and the LAGs (and/or link aggregation infrastructure provided by VLT) limited to the transmission of non-FCoE traffic. 
     Accordingly, it would be desirable to provide an improved link aggregated FCoE system. 
     SUMMARY 
     According to one embodiment, an Information Handling System (IHS) includes a communication subsystem; a processing system that is coupled to the communications subsystem; a memory system that is coupled to the processing system and that includes instructions that, when executed by the processing system, cause the processing system to provide a Fibre Channel Forwarding (FCF) engine that is configured to: receive, through the communication subsystem via a Link Aggregation Group (LAG), first Fibre Channel over Ethernet (FCoE) data traffic that is directed to a common FCF MAC address and that includes a first target device destination identifier; forward, through the communication subsystem in response to determining that the first target device destination identifier is associated with a first target device that is coupled to the communication subsystem, the first FCoE data traffic to the first target device; receive, through the communication subsystem via the LAG, second FCoE data traffic that is directed to the common FCF MAC address and that includes the second target device destination identifier; and forward, through the communication subsystem via an Inter-Chassis Link (ICL) in response to determining that the second target device destination identifier is associated with a second target device that is reachable through an FCF device that is coupled to the ICL, the second FCoE data traffic to the second FCF device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating an embodiment of an information handling system. 
         FIG. 2  is a schematic view illustrating an embodiment of a link aggregation FCoE system. 
         FIG. 3  is a schematic view illustrating an embodiment of an FCF device used in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 4  is a schematic view illustrating an embodiment of an FSB device used in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 5  is a flow chart illustrating an embodiment of a method for providing link aggregated FCoE communications. 
         FIG. 6A  is a swim lane diagram illustrating an embodiment of communications between devices the link aggregated FCoE system of  FIG. 2 . 
         FIG. 6B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 6A . 
         FIG. 7A  is a swim lane diagram illustrating an embodiment of communications between devices the link aggregated FCoE system of  FIG. 2 . 
         FIG. 7B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 7A . 
         FIG. 8A  is a swim lane diagram illustrating an embodiment of communications between devices the link aggregated FCoE system of  FIG. 2 . 
         FIG. 8B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 6A . 
         FIG. 9A  is a swim lane diagram illustrating an embodiment of communications between devices in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 9B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 9A . 
         FIG. 10A  is a swim lane diagram illustrating an embodiment of communications between devices in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 10B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 10A . 
         FIG. 11A  is a swim lane diagram illustrating an embodiment of communications between devices in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 11B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 11A . 
         FIG. 12A  is a swim lane diagram illustrating an embodiment of communications between devices in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 12B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 12A . 
         FIG. 13A  is a swim lane diagram illustrating an embodiment of communications between devices in the link aggregated FCoE system of  FIG. 2 . 
         FIG. 13B  is a schematic diagram illustrating an embodiment of the communications of  FIG. 13A . 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer (e.g., desktop or laptop), tablet computer, mobile device (e.g., personal digital assistant (PDA) or smart phone), server (e.g., blade server or rack server), a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, touchscreen and/or a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     In one embodiment, IHS  100 ,  FIG. 1 , includes a processor  102 , which is connected to a bus  104 . Bus  104  serves as a connection between processor  102  and other components of IHS  100 . An input device  106  is coupled to processor  102  to provide input to processor  102 . Examples of input devices may include keyboards, touchscreens, pointing devices such as mouses, trackballs, and trackpads, and/or a variety of other input devices known in the art. Programs and data are stored on a mass storage device  108 , which is coupled to processor  102 . Examples of mass storage devices may include hard discs, optical disks, magneto-optical discs, solid-state storage devices, and/or a variety other mass storage devices known in the art. IHS  100  further includes a display  110 , which is coupled to processor  102  by a video controller  112 . A system memory  114  is coupled to processor  102  to provide the processor with fast storage to facilitate execution of computer programs by processor  102 . Examples of system memory may include random access memory (RAM) devices such as dynamic RAM (DRAM), synchronous DRAM (SDRAM), solid state memory devices, and/or a variety of other memory devices known in the art. In an embodiment, a chassis  116  houses some or all of the components of IHS  100 . It should be understood that other buses and intermediate circuits can be deployed between the components described above and processor  102  to facilitate interconnection between the components and the processor  102 . 
     Referring now to  FIG. 2 , an embodiment of a link aggregated Fibre Channel over Ethernet (FCoE) system  200  is illustrated. In the specific embodiments discussed below, the link aggregation utilized in the link aggregated FCoE system  200  is provided via the Virtual Link Trunking (VLT) protocol, which a proprietary link aggregation protocol available from DELL® Technologies of Round Rock, Tex., United States. However, other link aggregation protocols may be utilized in place of the VLT protocol while remaining within the scope of the present disclosure. In the illustrated embodiment, the link aggregated FCoE system  200  includes a pair of Fibre Channel Forwarder (FCF) devices  202   a  and  202   b , although on of skill in the art will recognize that networks may (and typically will) include many more FCF devices. Each of the FCF devices  202   a  and  202   b  may be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific embodiment, the FCF devices  202   a  and  202   b  are provided by Fibre Channel switches that, as discussed below, provide for the transmittal of FCoE data traffic (as well as non-FCoE Ethernet data traffic) between computing devices. However, other types of computing devices may benefit from the teachings of the present disclosure, and thus are envisioned as falling within its scope. The FCF devices  202   a  and  202   b  are connected together by an Inter-Chassis Link (ICL)  204  such as, for example, a VLT interconnect (VLTi), that may include one or more connections between ICL port(s) on the FCF device  202   a  and one or more ports on the FCF device  202   b . In a specific embodiment, the FCF devices  202   a  and  202   b  are VLT peer devices. 
     In the illustrated embodiment, the FCF device  202   a  is coupled to a target device  206  via a Fibre Channel link. In an embodiment, the target device  206  may be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific embodiment, the target device  206  may be a Fibre Channel storage device, although other Fibre Channel fabric devices will fall within the scope of the present disclosure as well. The FCF device  202   a  is also coupled to a Converged Network Adapter (CNA) device  208  via one or more non-Link Aggregation Group (non-LAG) ports (also known as “orphan” ports). In an embodiment, the CNA device  208  may be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific example, the CNA device  208  may be provided on a server device to, for example, combine the functionality of a Host Bus Adapter (HBA) and a Network Interface Controller (NIC) to converge access to a Storage Area Network (SAN) along with a general purpose computer network. 
     Similarly, in the illustrated embodiment, the FCF device  202   b  is coupled to a target device  210  via a Fibre Channel link. In an embodiment, the target device  210  may be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific embodiment, the target device  210  may be a Fibre Channel storage device, although other Fibre Channel fabric devices will fall within the scope of the present disclosure as well. The FCF device  202   b  is also coupled to a Converged Network Adapter (CNA) device  212  via one or more non-LAG ports (also known as “orphan” ports). In an embodiment, the CNA device  212  may be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific example, the CNA device  212  may be provided on a server device to, for example, combine the functionality of a Host Bus Adapter (HBA) and a Network Interface Controller (NIC) to converge access to a Storage Area Network (SAN) along with a general purpose computer network. 
     A pair of CNA devices  214   a  and  214   b  are coupled to the FCF devices  202   a  and  202   b  via a LAG  216  that includes a plurality of LAG links between LAG ports on the CNA devices  214   a  and  214   b  and the FCF devices  202   a  and  202   b . In an embodiment, the CNA devices  214   a  and  214   b  may each be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific example, the CNA devices  214   a  and  214   b  may each be provided on a server device to, for example, combine the functionality of an HBA and a NIC to converge access to a SAN along with a general purpose computer network. In a specific embodiment, the LAG  216  is a VLT LAG associated with a first port channel (e.g., port channel  20 .) 
     A pair of CNA devices  218   a  and  218   b  are coupled to a Fibre Channel Initialization Protocol (FIP) Snooping Bridge (FSB) device  220  that is coupled to the FCF devices  202   a  and  202   b  via a LAG  222  that includes a plurality of LAG links between LAG ports on the FSB device  220  and the FCF devices  202   a  and  202   b . In an embodiment, the CNA devices  218   a  and  218   b  may each be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific example, the CNA devices  218   a  and  218   b  may each be provided on a server device to, for example, combine the functionality of a HBA and a NIC to converge access to a SAN along with a general purpose computer network. In an embodiment, the FSB device  220  may each be the IHS  100  discussed above with reference to  FIG. 1 , and/or may include some or all of the components of the IHS  100 . In a specific example, the FSB device  220  may each be a Fibre Channel switch device that is configured to snoop FIP packets during discovery and login in order to implement dynamic data integrity mechanisms (e.g., using Access Control Lists (ACLs)) to ensure that only valid FCoE traffic is allowed through the fabric. In a specific embodiment, the LAG  222  is a VLT LAG associated with a second port channel (e.g., port channel  10 .) While a specific link aggregated FCoE system  200  has been described for purposes of the discussions below, one of skill in the art in possession of the present disclosure will recognize that a variety of different devices and device configurations may be provided in a link aggregated FCoE system that will remain within the scope of the present disclosure. 
     Referring now to  FIG. 3 , an embodiment of an FCF device  300  is illustrated that may be either of the FCF devices  202   a  and  202   b  discussed above with reference to  FIG. 2 . As such, the FCF device  300  may be the IHS  100  discussed above with reference to  FIG. 1 , may include some or all of the components of the IHS  100 , and in specific embodiments may be a Fibre Channel switch that provides for the transmittal of FCoE data traffic (as well as non-FCoE Ethernet data traffic) between computing devices. In the illustrated embodiment, the FCF device  300  includes a chassis  302  that houses the components of the FCF device  300 , only some of which are illustrated in  FIG. 3 . For example, the chassis  302  may house a processing system (not illustrated, but which may include the processor  102  discussed above with reference to  FIG. 1 ) and a memory system (not illustrated, but which may include the memory  114  discussed above with reference to  FIG. 1 ) that includes instructions that, when executed by the processing system, cause the processing system to provide an FCF engine  304  that is configured to perform the functions of the FCF engines and FCF devices discussed below. 
     The chassis  302  may also house a storage device (not illustrated, but which may include the storage device  108  discussed above with reference to  FIG. 1 ) that is coupled to the FCF engine  304  (e.g., via a coupling between the storage device and the processing system) and that includes an FCF database  306  that stores data and/or other information utilized to provide the functionality discussed below. The chassis  302  may also house a communication subsystem  308  that is coupled to the FCF engine  304  (e.g., via a coupling between the communication subsystem  308  and the processing system) and that may include a Network Interface Controller (NIC), a wireless communication device (e.g., a BLUETOOTH® wireless communication device, a Near Field Communication (NFC) device, a WiFi communication devices, and/or other wireless communication devices known in the art), and/or other communication components known in the art. In a specific embodiment, the communication subsystem  308  may include the ports (e.g., the non-LAG ports, the LAG ports, and/or other ports discussed below) utilized for providing the links to target devices, CNA devices, and FSB devices discussed below. While a specific embodiment of an FCF device has been illustrated and described, one of skill in the art in possession of the present disclosure will recognize that FCF devices may include a variety of other components for providing conventional FCF device functionality, as well as the functionality discussed below, while remaining within the scope of the present disclosure. 
     Referring now to  FIG. 4 , an embodiment of an FSB device  400  is illustrated that may be either the FSB device  220  discussed above with reference to  FIG. 2 . As such, the FSB device  400  may be the IHS  100  discussed above with reference to  FIG. 1 , may include some or all of the components of the IHS  100 , and in specific embodiments may be a Fibre Channel switch device that is configured to snoop FIP packets during discovery and login in order to implement dynamic data integrity mechanisms (e.g., using ACLs) to ensure that only valid FCoE traffic is allowed through the fabric. In the illustrated embodiment, the FSB device  400  includes a chassis  402  that houses the components of the FSB device  400 , only some of which are illustrated in  FIG. 4 . For example, the chassis  402  may house a processing system (not illustrated, but which may include the processor  102  discussed above with reference to  FIG. 1 ) and a memory system (not illustrated, but which may include the memory  114  discussed above with reference to  FIG. 1 ) that includes instructions that, when executed by the processing system, cause the processing system to provide an FSB engine  404  that is configured to perform the functions of the FSB engines and FSB devices discussed below. 
     The chassis  402  may also house a storage device (not illustrated, but which may include the storage device  108  discussed above with reference to  FIG. 1 ) that is coupled to the FSB engine  404  (e.g., via a coupling between the storage device and the processing system) and that includes an FSB database  406  that stores data and/or other information utilized to provide the functionality discussed below. The chassis  402  may also house a communication subsystem  408  that is coupled to the FSB engine  404  (e.g., via a coupling between the communication subsystem  308  and the processing system) and that may include a Network Interface Controller (NIC), a wireless communication device (e.g., a BLUETOOTH® wireless communication device, a Near Field Communication (NFC) device, a WiFi communication devices, and/or other wireless communication devices known in the art), and/or other communication components known in the art. In a specific embodiment, the communication subsystem  408  may include the ports (e.g., the LAG ports, and/or other ports discussed below) utilized for providing the links to the FCF devices and CNA devices discussed below. While a specific embodiment of an FSB device has been illustrated and described, one of skill in the art in possession of the present disclosure will recognize that FSB devices may include a variety of other components for providing conventional FSB device functionality, as well as the functionality discussed below, while remaining within the scope of the present disclosure. 
     Referring now to  FIG. 5 , an embodiment of a method  500  for providing link aggregated FCoE communications is illustrated. As discussed below, the systems and methods of the present disclosure provide for the utilization of a link aggregated infrastructure (e.g., a VLT infrastructure) to achieve link level fault tolerance for FCoE traffic on link aggregated port channels (e.g., VLT port channels). The method  500  includes a variety of blocks, and one of skill in the art in possession of the present disclosure will recognize that in different embodiments, some blocks may not be performed. Furthermore, prior to or during the method  500 , a variety of actions may be performed to configure the link aggregated FCoE system  200  to perform the functionality described below. 
     For example, during the method  500 , the FCF devices  202   a  and  202   b  operating as link aggregated peer devices (e.g., VLT peers) act a single, logical FCF device when viewed from a device connected to the FCF devices  202   a  and  202   b  via a LAG (e.g., the CNA devices  214   a  and  214   b  connected to the LAG  206 , or the FSB device  220  connected to the LAG  222 ). This is enabled, at least in part, in response to a network administrator or other user assigning (e.g., via configuration commands) each of the FCF devices  202   a  and  202   b  a common FCF MAC address (e.g., each of the FCF devices  202   a  and  202   b  is associated with the same or “common” FCF MAC address) during, for example, the setup of the LAGs  216  and/or  222 . Furthermore, each of the FCF devices  202   a  and  202   b  may be assigned a respective local FCF MAC address (i.e., the FCF device  202   a  may be assigned a first local FCF MAC address, and the FCF device  202   b  may be assigned a second local FCF MAC address that is different than the first local FCF MAC address), and may sync or otherwise share that local FCF MAC address with the other FCF device. 
     As such, in the FCF device communications discussed below, different FCF MAC addresses may be used to communicate with the same FCF device. For example, CNA devices connected to non-LAG ports on the FCF devices  202   a  and  202   b  (e.g., the CNA device  208  and the CNA device  212  connected via orphan ports) will use local FCF MAC addresses to communicate with their directly connected FCF devices (e.g., the CNA device  208  will use the first local FCF MAC address discussed above to communicate with the FCF device  202   a , and the CNA device  212  will use the second local FCF MAC address discussed above to communication with the FCF device  202   b .) Meanwhile CNA devices connected to the FCF devices  202   a  and  202   b  via LAGs (e.g., the CNA devices  214   a ,  214   b ,  218   a , and  218   b ) will use the common FCF MAC address to communicate with the FCF devices  202   a  and  202   b.    
     In addition, before or during the method  500 , the target devices  206  and  210  may log in to their respective FCF devices  202   a  and  202   b  by, for example, providing fabric logins (FLOGIs) to that FCF device. That FCF device will then respond with a FLOGI accept, and perform a login information synchronization with the other FCF device. In addition, the target devices  206  and  210  may also provide port logins (PLOGIs) to their respective FCF devices, and those FCF devices will respond with a PLOGI accept, and perform a name server information synchronization with the other FCF device. 
     The method  500  may begin at block  502  where a first FCF device may assign identifier(s) to a non-LAG connected devices, and block  504  where a second FCF device may assign identifier(s) to a non-LAG connected devices. In an embodiment, at block  502 , the FCF engine  304  included in the FCF device  202   a / 300  may operate to assign a Fibre Channel identifier (FCID) to the target device  206  and the CNA device  208 , and at block  504  the FCF engine  304  included in the FCF device  202   b / 300  may operate to assign an FCID to the target device  210  and the CNA device  210 . As would be appreciated by one of skill in the art in possession of the present disclosure, the assignment of FCIDs may be based on domain identifiers, areas, port numbers, and/or other information. As such, using conventional FCID assignment methods, a device connected to port  1  on the FCF device  202   a  could be assigned the same FCID as a device connected to port  1  on the FCF device  202   b . However, at blocks  502  and  504 , the FCF devices  202   a  and  202   b  may operate to ensure that each FCID assigned to the devices is unique. In an embodiment, fabric port numbers and virtual fabric port numbers provided by the FCF device  202   b  may be logically extended (i.e., relative to fabric port numbers and virtual fabric port number provided by the FCF device  202   a ) by having the FCF device  202   a  utilize a first range of port numbers to assign FCIDs to its devices, and the FCF device  202   b  utilizes a second range of port numbers to assign FCIDs to its devices. For example, one of skill in the art in possession of the present disclosure will recognize that the assignment of unique FCIDs to the FCF devices (or other VLT peers) may be performed utilizing a variety of existing methods for FCID extension. 
     For example, the FCF device  202   a  may support 128 ports, and may utilize a first port number range of 1-128 for use in assigning fabric ports and virtual fabric ports. As such, if the FCF device  202   b  also supports 128 ports, the port number range of 129-256 may be utilized by the FCF device  202   b  for use in assigning fabric ports and virtual fabric ports. As such, each of the FCF devices  202   a  and  202   b  may be assigned a unique unit identifier (e.g., the FCF device  202   a  may be assigned “unit ID 1”, and the FCF device  202   b  may be assigned “unit ID 2”) in the link aggregation domain (e.g., the VLT domain), and each unique unit identifier may be associated with a different port number range so that each device connected to the FCF devices  202   a  and  202   b  via a non-LAG port is assigned a unique FCID (e.g., the CNA device  208  may be assigned an FCID based on the port number  1 , the target device  206  may be assigned an FCID based on the port number  2 , the CNA device  212  may be assigned an FCID based on the port number  129 , the target device  210  may be assigned an FCID based on the port number  130 ) by their respective FCF device. 
     The method  500  then proceeds to block  506  where the first FCF device may apply a first zoning configuration and synchronize the first zoning configuration with the second FCF device, and to block  508  where the first FCF device may synchronize a second zoning configuration applied by the second FCF device. In order to provide for the functionality discussed below, the zoning configurations in each of the FCF devices  202   a  and  202   b  should be identical. As such, at block  506 , the FCF engine  304  in the FCF device  202   a / 300  may operate to apply a first zoning configuration and then synchronize that first zoning configuration with the FCF device  202   b  (e.g., by sharing first zoning configuration information for the first zoning configuration through the communication subsystem  308  with the FCF device  202   b .) Similarly, at block  506 , the FCF engine  304  in the FCF device  202   b / 300  may operate to apply a second zoning configuration and then synchronize that second zoning configuration with the FCF device  202   a  (e.g., by sharing second zoning configuration information for the second zoning configuration through the communication subsystem  308  with the FCF device  202   a ) such that the FCF device  202   a  synchronizes the second zoning configuration that was applied by the FCF device  202   b . As would be understood by one of skill in the art in possession of the present disclosure, such zoning configurations may apply to devices connected to both LAG ports and non-LAG ports on the FCF devices  202   a  and  202   b . Furthermore, in some embodiments, the FCF engines  304  in the FCF devices  202   a  and  202   b  may include a synchronization mechanism that operates to periodically synchronize zoning configurations across the FCF devices  202   a  and  202   b , while in other embodiments, the FCF engines  304  in the FCF devices  202   a  and  202   b  may operate to determine mismatches between zoning configurations on the FCF devices  202   a  and  202   b  and then report those mismatches to a network administrator (e.g., in response to a “show zoning configuration mismatches” command.) In specific examples, the FCF engines  304  in the FCF devices  202   a  and  202   b  may be configured to correct mismatches between zoning configurations in the FCF devices  202   a  and  202   b  to ensure that the zoning configurations on the FCF devices  202   a  and  202   b  are identical in order to ensure that communication between the FCF devices  202   a  and  202   b  is not disrupted. Furthermore, in other examples, the synchronization of zoning configurations may not be performed automatically and, rather, a network administrator may simply apply the same zoning configurations to the FCF devices  202   a  and  202   b.    
     The method  500  then proceeds to block  510  where the first FCF device may handle first control traffic received via a LAG, and to block  512  where the first FCF device may handle second control traffic forwarded by the second FCF device via an ICL. In an embodiment, at or prior to the method  500 , a primary link aggregation device and a second link aggregation device may be designated from the FCF devices in the link aggregated FCoE system  200 , with the primary link aggregation device controlling handling control data traffic received on a LAG, and the secondary link aggregation device providing control data traffic received on a LAG to the primary link aggregation node device. The designation of the primary link aggregation node and the secondary link aggregation node may be based on election mechanisms known in the art (e.g., lowest MAC address). In specific examples provided below, the FCF device  202   a  is designated as a primary link aggregation device, while the FCF device  202   b  is designated as a secondary link aggregation device. At block  510 , the FCF engine  304  in the FCF device  202   a / 300  may receive first control data traffic through the communication subsystem  308  via either of the LAGs  216  or  222  and, in response, handle that first control data traffic. At block  512 , the FCF engine  304  in the FCF device  202   b / 300  may receive second control data traffic through the communication subsystem  308  via either of the LAGs  216  or  222  and, in response, tunnel that second control data traffic through the ICL  204  to the FCF device  202   a  (e.g., while providing that second control data traffic with a link aggregation header such as a VLT header) so that the FCF device  202   a  may handle that second control data traffic as well. 
     In an embodiment, the control data traffic handled by the primary link aggregation device at blocks  510  and  512  may include control data traffic that is received during FCoE Initialization Protocol (FIP) communications (as well as other FCoE data traffic) that includes a DID and a well-defined fibre channel address. In one example, the primary link aggregation device (e.g., the FCF device  202   a  in the example above) may receive control data traffic directly from the FSB device  220  (e.g., due to the FSB device  220  selecting links in the LAG  222  that are directly connected to the FCF device  202   a , discussed below), and then operate to respond to the control data traffic and populate its FCF device tables (e.g., in its FCF database  306 ), as well as synchronize the information in its FCF device tables with the secondary link aggregation device (e.g., the FCF device  202   b  in the example above) by sending synchronization information to the secondary link aggregation node device. In such examples, the secondary link aggregation device may operate to use that synchronization information to populate its FCF device tables (e.g., in its FCF database  306 .) 
     In another example, the secondary link aggregation device (e.g., the FCF device  202   b  in the example above) may receive control data traffic directly from the FSB device  220  (e.g., due to the FSB device  220  selecting links in the LAG  222  that are directly connected to the FCF device  202   b , discussed below), and then operate to tunnel the control data traffic to the primary link aggregation device (e.g., the FCF device  202   a  in the example above) via the ICL  204  (e.g., by providing the control data traffic with link aggregation header information (e.g., VLT header information) and LAG information (e.g., VLT LAG information) that identifies the links on which that control data traffic were received. The primary link aggregation device may then treat the control data traffic as if it were received locally via the LAG  222  and operate to respond to the control data traffic and populate its FCF device tables (e.g., in its FCF database  306 ), as well as synchronize the information in its FCF device tables with the secondary link aggregation device (e.g., the FCF device  202   b  in the example above) by sending synchronization information to the secondary link aggregation node device, similarly as discussed above. 
     As such, for control data traffic, the FCF devices  202   a  and  202   b  may operate to maintain a table (e.g., in their FCF databases  306 ) for login entries. For example, such a table may include fields for FCIDs, enode MAC addresses, port numbers, and whether connections are local or remote. For virtual fabric port logins, enode MAC addresses may be synced in each of the tables in the FCF devices  202   a  and  202   b , while for fabric port logins, only the FCIDs may be synced in each of the tables in the FCF devices  202   a  and  202   b . Furthermore, when the target port on the FCF device  202   a  is an orphan port, the FCF device  202   b  may operate to update its FCF device tables as information is learned on the ICL  204 . In addition, a table may also be maintained (in the FCF databases  306 ) for name server entries. For example, such a table may include fields for FCIDs, interfaces, enode World Wide Port Numbers (WWPNs), enode World Wide Node Names (WWNNs), classes of service, and whether connections are local or remote. As such, hardware table programming (e.g., programming of Access Control Lists (ACLs) for virtual fabric ports (e.g., VLT ports)) may be replicated for the ICL  204  as well, and may be performed in both of the FCF devices  202   a  and  202   b  (e.g., the VLT peers.) One of skill in the art in possession of the present disclosure will recognize that these programming actions will allow data traffic to be received (e.g., by the FCF device  202   a ) on a LAG (e.g., one of the LAGs  216  or  220 ) when the LAG ports are available, while allowing data traffic to be received on the ICL  204  if there is a failure of links in the LAGs (e.g., the links to the FCF device  202   a .) 
     The method  500  then proceeds to blocks  514 ,  516 ,  518 , and  520  where FCoE data traffic is routed from CNA devices to target devices. As discussed below, the behavior of the FCF devices  202   a  and  202   b  may change depending on which CNA device is communicating with which target device. As such, examples of a variety of those scenarios are provided below. In some embodiments, the first FCoE data traffic received by either of the FCF devices  202   a  and  202   b  may have been forwarded by the FSB engine  404  in the FSB device  220  from either of the CNA devices  218   a  or  218   b . As would be appreciated by one of skill in the art in possession of the present disclosure, using conventional forwarding methods, the FSB device  220  may select any link in the LAG  222  (e.g., based on a hashing algorithm) through which to forward the first FCoE data traffic received from either of the CNA devices  218   a  and  218   b . However, if the FSB device  220  selects a link to an FCF device that is not directly connected to the target device for which the first FCoE data traffic is destined, that first FCoE data traffic will then need to be forwarded through the ICL  204  in order to reach the target device for which the first FCoE data traffic is destined (e.g., via the directly connected FCF device), which can provide for inefficient routing of the first FCoE data traffic. In order to ensure efficient routing of all FCoE data traffic, the FSB device  220  in the link aggregated FCoE system  200  attempts to forward FCoE data traffic to the FCF device that is directly connected to the target device for which that FCoE data traffic is destined. 
     For example, the FSB device  220  may learn its neighboring devices using the Link Layer Discovery Protocol (LLDP) operating on the links between the FSB device  220  and the FCF devices  202   a  and  202   b . Using remote MAC addresses learned during LLDP packet exchanges, the FSB device  220  may then determine which of the links in the LAG  222  are connected to the FCF device  202   a , and which of the links in the LAG  222  are connected to the FCF device  202   b . As such, the FSB device  220  may create different trunks associated with the links. For example, the FSB device  220  may create a first trunk associated with (e.g., having ports connected to) all of the links in the LAG  222 , a second trunk associated with (e.g., having ports connected to) the link(s) in the LAG  222  that are connected to the FCF device  202   a , and a third trunk associated with (e.g., having ports connected to) the link(s) in the LAG  222  that are connected to the FCF device  202   b . As such, non-FCoE Ethernet data traffic may be associated with a first Virtual Local Area Network (VLAN) that is forwarded using the first trunk (i.e., all the links in the LAG  222 ), while FCoE data traffic may be associated with a second VLAN that is forwarded using the second trunk and the third trunk. 
     The FSB device  220  may then send FCoE data traffic to its destined target device using either the second trunk or the third trunk based on knowledge of which of the FCF devices  202   a  and  202   b  that target device is connected to. For example, the FCF engine  304  in each of the FCF devices  202   a  and  202   b  may be configured to send its unit identifier (discussed above) and its total number of ports in a Type-Length-Value (TLV) structure of an LLDP data packet. As discussed above, the FCID assigned to the devices connected to non-LAG ports on the FCF devices  202   a  and  202   b  may be based on the unit identifiers for those FCF devices and the port number of the port connected to those devices, and the sharing of this information with the FSB device  220  allows the FSB engine  404  in the FSB device  220 / 400  to determine which FCF device is connected to which target device. As such, the FSB device  220  may then determine which trunk to use to reach a particular target device. Furthermore, the FSB device  220  may apply ingress Access Control Lists (ACLs), and forward FCoE data traffic to target devices based on the FCID of those target devices and using the trunk associated with its directly connected FCF device. In other embodiments, methods/protocols other than LLDP may be utilized such as, for example, the FCoE initialization protocol (or other protocols understood by the FSB device  220 .) 
     As such, in some embodiments of the method  500 , at block  514  the first FCF device receives first FCoE data traffic through the LAG that is directed to a common FCF MAC address and that identifies the first target device, and at block  516  the first FCF device will forward the first FCoE data traffic to the first target device. In an embodiment, at block  514 , the FCF engine  304  in the FCF device  202   a / 300  may receive first FCoE data traffic via the LAG  216  or via the LAG  222 . Such first FCF data traffic will include the common FCF MAC address as its destination MAC address, and may include a target device destination identifier (DID) that identifies the target device  206 . At block  514 , the FCF engine  204  in the FCF device  202   a / 300  will then identify the target device  208  using the target device DID, and then forward the first FCoE data traffic to the target device  206  at block  516 . 
     In some embodiments of the method  500 , at block  518  the first FCF device receives second FCoE data traffic through the LAG that is directed to a common FCF MAC address and that identifies the second target device, and at block  520  the first FCF device then forwards the second FCoE data traffic to the second FCF device. For example, the links in the LAG  216  that are connected to the FCF device  202   b , or the links in the LAG  222  that are connected to the FCF device  202   b , may be unavailable, requiring that the second FCoE data traffic destined for the target device  210  be initially sent to the FCF device  202   a . In an embodiment, at block  518 , the FCF engine  304  in the FCF device  202   a / 300  may receive second FCoE data traffic via the LAG  216  or via the LAG  222 . Such second FCF data traffic will include the common FCF MAC address as its destination MAC address, and may include a target device DID that identifies the target device  210 . At block  520 , the FCF engine  304  in the FCF device  202   a / 300  will then identify the target device  210  using the target device DID. The FCF engine  304  in the FCF device  202   a / 300  may then determine that the target device  210  is learned on the ICL  204  and, in response, forward the second FCoE data traffic through the ICL  204  (i.e., at the layer 2 level) to the FCF device  202   b . The FCF engine  304  in the FCF device  202   b / 300  will then forward that second FCoE data traffic to the target device  210 . 
     In situations where the CNA devices directly connected to non-LAG ports on an FCF device send FCoE data traffic to the target device directly connected to that FCF device, those CNA devices may use the local FCF MAC address for that FCF device. For example, the CNA devices  208  or  214   a  directly connected to the FCF device  202   a  may send FCoE data traffic to the FCF device  202   a  with the first local FCF MAC address (discussed above) as its destination MAC address, and a target device DID that identifies the target device  206 , and the FCF device  202   a  will forward that FCoE data traffic to the target device  206 . The CNA  212  may communicate with the target device  210  in substantially the same manner. Furthermore, in situations where the CNA devices directly connected to non-LAG ports on an FCF device send FCoE data traffic to a target device directly connected to a different FCF device, those CNA devices may use the local FCF MAC address for the directly connected FCF device as well. For example, the CNA devices  208  or  214   a  directly connected to the FCF device  202   a  may send FCoE data traffic to the FCF device  202   a  with the first local FCF MAC address (discussed above) as its destination MAC address, and a target device DID that identifies the target device  210 , and the FCF device  202   a  will then change the destination MAC address to the second local FCF MAC address (discussed above) and send that FCoE data traffic through the ICL  204  to the FCF device  202   b , with the FCF device  202   b  forwarding that FCoE data traffic to the target device  210 . The CNA  212  may communicate with the target device  208  in substantially the same manner. 
     In situations like those described above with the CNA devices  208  or  214   a  connecting to the target device  210 , each of the FCF devices  202   a  and  202   b  may maintain a table (e.g., in their FCF databases  306 ) for login entries. For example, such a table may include fields for FCIDs, enode MAC addresses, port numbers, and whether connections are local or remote. For virtual fabric port logins, enode MAC addresses may be synced along with the FCIDs in each of the tables in the FCF devices  202   a  and  202   b , while for fabric port logins, only the FCIDs may be synced in each of the tables in the FCF devices  202   a  and  202   b . In addition, a table may also be maintained (in the FCF databases  306 ) for name server entries. For example, such a table may include fields for FCIDs, interfaces, enode World Wide Port Numbers (WWPNs), enode World Wide Node Names (WWNNs), classes of service, and whether connections are local or remote. Because logins from the CNA devices to the target devices are performed on interfaces connected to a particular FCF device, the other FCF device will update its table as both are learned on the ICL  204 . In addition, the name server database would also point to the ICL  204 . 
     As would be appreciated by one of skill in the art in possession of the present disclosure, conventional CNA devices transmitting FCoE data traffic are generally not aware when they are communicating via a LAG and, as such, may operate to transmit data traffic using advertised FCF MAC addresses from the FCF devices (e.g., the local FCF MAC addresses discussed above). However, the link aggregated FCoE system  200  allows network administrators to configure the LAG for the FCF devices whether it is connected to a “LAG-aware” CNA device transmitting FCoE data traffic, or a “LAG-unaware” CNA device transmitting FCoE data traffic. In situations where a LAG-aware CNA devices are present on the LAG, the FCF devices may advertise the common FCF MAC addresses discussed above. However, in situations where a LAG-unaware CNA devices are present on the LAG, the FCF devices may advertise the local FCF MAC addresses discussed above This allows the different functionality of the FCF devices discussed above, as the FCF devices are also unaware of whether they are communicating via a LAG with directly connected CNA devices or CNA devices connected via an FSB device. 
     The link aggregated FCoE system  200  may also be configured to respond to a variety of failure scenarios. In one failure scenario example, if a link in one of the LAGs  216  or  222  to the FCF device  202   a  becomes unavailable, data traffic may be send to the FCF device  202   b . For example, the FCF device  202   b  will look up the destination MAC address and target device DID, and forward the data traffic based on that lookup (e.g., to the FCF device  202   a  via the ICL  204  if the target device DID identifies the target device  206 , or directly to the target device  210  if the target device DID identifies the target device  210 .) Similarly, if the link(s) in the LAG  222  to the FCF device  202   a  become unavailable, the FSB device  220  may change the trunk associations (discussed above) so that data traffic flow is to the FCF device  202   b  with the available links in the LAG  222 . 
     In another failure scenario example, the ICL  204  may become unavailable. In response to unavailability of the ICL  204 , the secondary link aggregation device (e.g., the FCF device  202   b  in the example above) will operate to bring down all the LAG ports to the LAGs  216  and  222 . As such, communications with devices connected to the LAGs  216  and  222  will be unavailable, but communications between non-LAG/directly connected devices (e.g., the CNA devices  208 ,  212  and the target devices  206 / 210  connected via orphan ports) will be available. In such situations, if a login entry is cleared due to the unavailable ICL  204 , the primary and/or secondary link aggregation device may send Registered State Change Notifications (RSCNs) to their directly connected target devices. Furthermore, if login entries are cleared due to the unavailability of the LAG to the secondary link aggregation device, the secondary link aggregation device may send RSCNs to its directly connected target device as well. Finally, any session changes in such situations will be reflected in ACLs as well. 
     In situations where the ICL  204  becomes unavailable and then subsequently becomes available again, the primary link aggregation device will operate to synchronize login information and name server information in its FCF database  306  with the secondary link aggregation node device. Furthermore, the secondary link aggregation node device will operate to synchronize the locally learned login and name server information in its FCF database  306  with the primary link aggregation device. Following availability of the ICL  204 , the secondary link aggregation device will operate to make the LAGs  216  and  222  available again so that data traffic may be sent over those LAGs to both FCF devices  202   a  and  202   b . Similarly as discussed above, any session changes in such situations will be reflected in ACLs as well. 
     In yet another failure scenario example, one of the FCF devices  202   a  or  202   b  may reboot or otherwise become unavailable. In such situations, communications through the LAGs  216  and  222  that are directed to a target device connected to the unavailable FCF device will be unavailable, but communications through the LAGs  216  and  222  that are directed to a target device connected to the available FCF device will be available. If any login entries are cleared due to the FCF device unavailability, the FCF device acting as the primary link aggregation device (e.g., the FCF device  202   a  if the FCF device  202   b  is unavailable, or the FCF device  202   b  if the FCF device  202   a  is unavailable and the FCF device  202   b  changes from acting as the secondary link aggregation device to acting as the primary link aggregation device) will operate to send RSCNs to its directly connected target device. Similarly as discussed above, any session changes in such situations will be reflected in ACLs as well. 
     In situations where FCF device becomes unavailable and then subsequently becomes available again, it will normally begin acting as a secondary link aggregation device. In such situations, the primary link aggregation device will operate to synchronize login information and name server information in its FCF database  306  with the secondary link aggregation node device. Furthermore, the secondary link aggregation node device will operate to synchronize the locally learned login and name server information in its FCF database  306  with the primary link aggregation device. Further still, the secondary link aggregation device will operate to make the LAGs  216  and  222  available again so that data traffic may be sent over those LAGs to both FCF devices  202   a  and  202   b . Similarly as discussed above, any session changes in such situations will be reflected in ACLs as well. 
     While a few failure scenarios have been described, one of skill in the art in possession of the present disclosure will recognize that other situations may be dealt with as well. For example, if links in a LAG to one of the FCF devices  202   a  and  202   b  become unavailable, login entries may not be cleared, while if links in a LAG to both of the FCF devices  202   a  and  202   b  become unavailable, the login entries learned on that LAG may be cleared and RSCNs may be sent to the target devices by the primary link aggregation node. In another example, if an orphan link (i.e., a link to an orphan port) becomes unavailable, login information may be cleared in both of the FCF devices  202   a  and  202   b , and RCSNs may be sent to the target devices. In yet another example, state change notifications may be sent by each FCF device based on zoning configurations and synced/local login information, and whenever a device logs in or out of the fabric, the login information may be synced and each FCF device  202   a  and  202   b  may send RSCNs to its directly connected devices based on the zoning configuration details. As such, a wide variety of functionality may be performed to enable the link aggregation FCoE systems discussed above while remaining within the scope of the present disclosure. 
     The discussion below provides several specific examples of how control data traffic and FCoE data traffic may be handled by the link aggregated FCoE system  200  using the teachings discussed above. However, one of skill in the art in possession of the present disclosure will recognize that a variety of other data traffic communications may be handled in the link aggregated FCoE system  200  while remaining within the scope of the present disclosure as well. In the examples, below, the FCF device  202   a  is a primary link aggregation device (referred to below as the primary FCF device  202   a ), and the FCF device  202   b  is a secondary link aggregation device (referred to below as the secondary FCF device  202   b .) 
     Referring first to  FIGS. 6A and 6B , communications are illustrated between the CNA device  218   a  and the target device  206  when data traffic is forwarded by the FSB device  220  to the primary FCF device  202   a . As such, discussions of the CNA device  218   a  sending communications to the primary FCF device  202   a  below assume the forwarding of those communications by the FSB device  220  to the primary FCF device  202   a , and discussions of the primary FCF device  202   a  sending communications to the CNA device  218   a  below assume the forwarding of those communications by the FSB device  220  to the CNA device  218   a . One of skill in the art in possession of the present disclosure will recognize that similar operations may be performed by the primary FCF device  202   a  and the target device  206  when the CNA device  208  communicates with the target device  206 , with the exception that the CNA device  208  communicates directly with the primary FCF device  202   a  (rather than through the FSB device  220 .) 
     As illustrated in  FIGS. 6A and 6B , the CNA device  218   a  may send the primary FCF device  202   a  a VLAN discovery request communication  600  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a VLAN discovery notification communication  602 . The CNA device  218   a  may then send the primary FCF device  202   a  an FCF discovery solicitation communication  604  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  an FCF discovery advertisement communication  606 . The CNA device  218   a  may then send the primary FCF device  202   a  a fabric login (FLOGI) communication  608  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a FLOGI accept communication  610  and may also perform a login information synchronization operation  612  with the secondary FCF device  202   b . The CNA device  218   a  may then send the primary FCF device  202   a  a port login (PLOGI) communication  614  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a PLOGI accept communication  616  and may also perform a name server registration information synchronization operation  618  with the secondary FCF device  202   b . The CNA device  218   a  may then send the primary FCF device  202   a  PLOGI-to-target or data-traffic-to-target communications  620  and, in response, the primary FCF device  202   a  may forward those PLOGI-to-target or data-traffic-to-target communications  620  to the target device  206 , while the target device  206  may send to the primary FCF device  202   a  PLOGI accept or data traffic communications  622 , and the primary FCF device  202   a  may forward those PLOGI accept or data traffic communications  622  to the CNA device  218   a.    
     Referring next to  FIGS. 7A and 7B , communications are illustrated between the CNA device  218   a  and the target device  206  when data traffic is forwarded by the FSB device  220  to the secondary FCF device  202   b . As such, discussions of the CNA device  218   a  sending communications to the secondary FCF device  202   b  below assume the forwarding of those communications by the FSB device  220  to the secondary FCF device  202   b , and discussions of the primary FCF device  202   a  sending communications to the CNA device  218   a  below assume the forwarding of those communications by the FSB device  220  to the CNA device  218   a.    
     As illustrated in  FIGS. 7A and 7B , the CNA device  218   a  may send the secondary FCF device  202   b  a VLAN discovery request communication  700  and, in response, the secondary FCF device  202   b  may perform a request tunnel operation  702  to provide the VLAN discovery request communication  700  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a VLAN discovery notification communication  704 . The CNA device  218   a  may then send the secondary FCF device  202   b  an FCF discovery solicitation communication  706  and, in response, the secondary FCF device  202   b  may perform a solicitation tunnel operation  708  to provide the FCF discovery solicitation communication  706  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  an FCF discovery advertisement communication  710 . The CNA device  218   a  may then send the secondary FCF device  202   b  a fabric login (FLOGI) communication  712  and, in response, the secondary FCF device  202   b  may perform a FLOGI tunnel operation  714  to provide the FLOGI communication  712  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a FLOGI accept communication  716 , and also performing a login information synchronization operation  718  with the secondary FCF device  202   b . The CNA device  218   a  may then send the secondary FCF device  202   b  a port login (PLOGI) communication  720  and, in response, the secondary FCF device  202   b  may perform a PLOGI tunnel operation  722  to provide the PLOGI communication  720  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a PLOGI accept communication  724 , and also performing a name server registration information synchronization operation  726  with the secondary FCF device  202   b . The CNA device  218   a  may then send the secondary FCF device  202   b  PLOGI-to-target or data-traffic-to-target communications  728  and, in response, the secondary FCF device  202   b  may perform a ICL traffic forwarding operation  722  to provide the PLOGI-to-target or data-traffic-to-target communications  728  to the primary FCF device  202   a , with the primary FCF device  202   a  sending those PLOGI-to-target or data-traffic-to-target communications  728  to the target device  206 . The target device  206  may then send to the primary FCF device  202   a  PLOGI accept or data traffic communications  732 , and the primary FCF device  202   a  may forward those PLOGI accept or data traffic communications  732  to the CNA device  218   a.    
     Referring now to  FIGS. 8A and 8B , communications are illustrated between the CNA device  218   a  and the target device  210  when data traffic is forwarded by the FSB device  220  to the primary FCF device  202   a . As such, discussions of the CNA device  218   a  sending communications to the primary FCF device  202   a  below assume the forwarding of those communications by the FSB device  220  to the primary FCF device  202   a , and discussions of each of the primary FCF device  202   a  and the secondary FCF device  202   b  sending communications to the CNA device  218   a  below assume the forwarding of those communications by the FSB device  220  to the CNA device  218   a.    
     As illustrated in  FIGS. 8A and 8B , the CNA device  218   a  may send the primary FCF device  202   a  a VLAN discovery request communication  800  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a VLAN discovery notification communication  802 . The CNA device  218   a  may then send the primary FCF device  202   a  an FCF discovery solicitation communication  804  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  an FCF discovery advertisement communication  806 . The CNA device  218   a  may then send the primary FCF device  202   a  a fabric login (FLOGI) communication  808  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a FLOGI accept communication  810  and may also perform a login information synchronization operation  812  with the secondary FCF device  202   b . The CNA device  218   a  may then send the primary FCF device  202   a  a port login (PLOGI) communication  814  and, in response, the primary FCF device  202   a  may send the CNA device  218   a  a PLOGI accept communication  816  and may also perform a name server registration information synchronization operation  818  with the secondary FCF device  202   b . The CNA device  218   a  may then send the primary FCF device  202   a  PLOGI-to-target or data-traffic-to-target communications  820  and, in response, the primary FCF device  202   a  may perform an ICL traffic forwarding operation  822  to forward the PLOGI-to-target or data-traffic-to-target communications  820  to the secondary FCF device  202   b , with the second FCF device  202   b  forwarding the PLOGI-to-target or data-traffic-to-target communications  820  to the target device  206 . The target device  206  may send to the secondary FCF device  202   b  PLOGI accept or data traffic communications  824 , and the secondary FCF device  202   b  may forward those PLOGI accept or data traffic communications  824  to the CNA device  218   a.    
     Referring next to  FIGS. 9A and 9B , communications are illustrated between the CNA device  218   a  and the target device  210  when data traffic is forwarded by the FSB device  220  to the secondary FCF device  202   b . As such, discussions of the CNA device  218   a  sending communications to the secondary FCF device  202   b  below assume the forwarding of those communications by the FSB device  220  to the secondary FCF device  202   b , and discussions of the secondary FCF device  202   b  sending communications to the CNA device  218   a  below assume the forwarding of those communications by the FSB device  220  to the CNA device  218   a.    
     As illustrated in  FIGS. 9A and 9B , the CNA device  218   a  may send the secondary FCF device  202   b  a VLAN discovery request communication  900  and, in response, the secondary FCF device  202   b  may perform a request tunnel operation  902  to provide the VLAN discovery request communication  700  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a VLAN discovery notification communication  904 . The CNA device  218   a  may then send the secondary FCF device  202   b  an FCF discovery solicitation communication  906  and, in response, the secondary FCF device  202   b  may perform a solicitation tunnel operation  908  to provide the FCF discovery solicitation communication  906  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  an FCF discovery advertisement communication  910 . The CNA device  218   a  may then send the secondary FCF device  202   b  a fabric login (FLOGI) communication  912  and, in response, the secondary FCF device  202   b  may perform a FLOGI tunnel operation  914  to provide the FLOGI communication  712  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a FLOGI accept communication  916 , and also performing a login information synchronization operation  918  with the secondary FCF device  202   b . The CNA device  218   a  may then send the secondary FCF device  202   b  a port login (PLOGI) communication  920  and, in response, the secondary FCF device  202   b  may perform a PLOGI tunnel operation  922  to provide the PLOGI communication  920  to the primary FCF device  202   a , with the primary FCF device  202   a  sending the CNA device  218   a  a PLOGI accept communication  924 , and also performing a name server registration information synchronization operation  926  with the secondary FCF device  202   b . The CNA device  218   a  may then send the secondary FCF device  202   b  PLOGI-to-target or data-traffic-to-target communications  928  and, in response, the secondary FCF device  202   b  forwarding those PLOGI-to-target or data-traffic-to-target communications  928  to the target device  206 . The target device  206  may then send to the secondary FCF device  202   b  PLOGI accept or data traffic communications  930 , and the secondary FCF device  202   b  may forward those PLOGI accept or data traffic communications  930  to the CNA device  218   a.    
     Referring now to  FIGS. 10A and 10B , communications are illustrated between the CNA device  214   a  and the target device  206 . As illustrated in  FIGS. 10A and 10B , the CNA device  214   a  may send the primary FCF device  202   a  a VLAN discovery request communication  1000  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a VLAN discovery notification communication  1002 . The CNA device  214   a  may then send the primary FCF device  202   a  an FCF discovery solicitation communication  1004  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  an FCF discovery advertisement communication  1006 . The CNA device  214   a  may then send the primary FCF device  202   a  a fabric login (FLOGI) communication  1008  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a FLOGI accept communication  1010  and may also perform a login information synchronization operation  1012  with the secondary FCF device  202   b . The CNA device  214   a  may then send the primary FCF device  202   a  a port login (PLOGI) communication  1014  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a PLOGI accept communication  1016  and may also perform a name server registration information synchronization operation  1018  with the secondary FCF device  202   b . The CNA device  214   a  may then send the primary FCF device  202   a  PLOGI-to-target or data-traffic-to-target communications  1020  and, in response, the primary FCF device  202   a  may forward the PLOGI-to-target or data-traffic-to-target communications  1020  to the target device  206 . The target device  206  may send to the primary FCF device  202   a  PLOGI accept or data traffic communications  1022 , and the primary FCF device  202   a  may forward those PLOGI accept or data traffic communications  1022  to the CNA device  214   a.    
     Referring now to  FIGS. 11A and 11B , communications are illustrated between the CNA device  214   b  and the target device  210 . As illustrated in  FIGS. 11A and 11B , the CNA device  214   b  may send the secondary FCF device  202   b  a VLAN discovery request communication  1100  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a VLAN discovery notification communication  1102 . The CNA device  214   b  may then send the secondary FCF device  202   b  an FCF discovery solicitation communication  1104  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  an FCF discovery advertisement communication  1106 . The CNA device  214   b  may then send the secondary FCF device  202   b  a fabric login (FLOGI) communication  1108  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a FLOGI accept communication  1110  and may also perform a login information synchronization operation  1112  with the primary FCF device  202   a . The CNA device  214   b  may then send the secondary FCF device  202   b  a port login (PLOGI) communication  1114  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a PLOGI accept communication  1116  and may also perform a name server registration information synchronization operation  1118  with the primary FCF device  202   a . The CNA device  214   b  may then send the secondary FCF device  202   b  PLOGI-to-target or data-traffic-to-target communications  1120  and, in response, the secondary FCF device  202   b  may forward the PLOGI-to-target or data-traffic-to-target communications  820  to the target device  210 . The target device  210  may send to the secondary FCF device  202   b  PLOGI accept or data traffic communications  1122 , and the secondary FCF device  202   b  may forward those PLOGI accept or data traffic communications  1122  to the CNA device  214   b.    
     Referring now to  FIGS. 12A and 12B , communications are illustrated between the CNA device  214   a  and the target device  210 . One of skill in the art in possession of the present disclosure will recognize that similarly operations may be performed by the primary FCF device  202   a , the secondary FCF device  202   b , and the target device  210  when the CNA device  208  communicates with the target device  210 . As illustrated in  FIGS. 12A and 12B , the CNA device  214   a  may send the primary FCF device  202   a  a VLAN discovery request communication  1200  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a VLAN discovery notification communication  1202 . The CNA device  214   a  may then send the primary FCF device  202   a  an FCF discovery solicitation communication  1204  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  an FCF discovery advertisement communication  1206 . The CNA device  214   a  may then send the primary FCF device  202   a  a fabric login (FLOGI) communication  1208  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a FLOGI accept communication  1210  and may also perform a login information synchronization operation  1212  with the secondary FCF device  202   b . The CNA device  214   a  may then send the primary FCF device  202   a  a port login (PLOGI) communication  1214  and, in response, the primary FCF device  202   a  may send the CNA device  214   a  a PLOGI accept communication  1216  and may also perform a name server registration information synchronization operation  1218  with the secondary FCF device  202   b . The CNA device  214   a  may then send the primary FCF device  202   a  PLOGI-to-target or data-traffic-to-target communications  1220  and, in response, the primary FCF device  202   a  may perform an ICL traffic forwarding operation  1222  to forward the PLOGI-to-target or data-traffic-to-target communications  1220  to the secondary FCF device  202   b , with the second FCF device  202   b  forwarding the PLOGI-to-target or data-traffic-to-target communications  1220  to the target device  210 . The target device  210  may send to the secondary FCF device  202   b  PLOGI accept or data traffic communications  1224  and, in response, the secondary FCF device  202   b  may perform an ICL traffic forwarding operation  1226  to forward the PLOGI accept or data traffic communications  1224  to the primary FCF device  202   a , with the primary FCF device  202   a  forwarding those PLOGI accept or data traffic communications  1224  to the CNA device  214   a.    
     Referring now to  FIGS. 13A and 13B , communications are illustrated between the CNA device  214   b  and the target device  206 . As illustrated in  FIGS. 13A and 13B , the CNA device  214   b  may send the secondary FCF device  202   b  a VLAN discovery request communication  1300  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a VLAN discovery notification communication  1302 . The CNA device  214   b  may then send the secondary FCF device  202   b  an FCF discovery solicitation communication  1304  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  an FCF discovery advertisement communication  1306 . The CNA device  214   b  may then send the secondary FCF device  202   b  a fabric login (FLOGI) communication  1308  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a FLOGI accept communication  1310  and may also perform a login information synchronization operation  1312  with the primary FCF device  202   a . The CNA device  214   b  may then send the secondary FCF device  202   b  a port login (PLOGI) communication  1314  and, in response, the secondary FCF device  202   b  may send the CNA device  214   b  a PLOGI accept communication  1316  and may also perform a name server registration information synchronization operation  1318  with the primary FCF device  202   a . The CNA device  214   b  may then send the secondary FCF device  202   b  PLOGI-to-target or data-traffic-to-target communications  1320  and, in response, the secondary FCF device  202   b  may perform ICL traffic forwarding operations  1322  to forward the PLOGI-to-target or data-traffic-to-target communications  1320  to the primary FCF device  202   a , with the primary FCF device  202   a  forwarding the PLOGI-to-target or data-traffic-to-target communications  1320  to the target device  206 . The target device  206  may then send to the secondary FCF device  202   b  PLOGI accept or data traffic communications  1324 , and, in response, the secondary FCF device  202   b  may perform ICL traffic forwarding operations  1326  to forward those PLOGI accept or data traffic communications  1324  to the primary FCF device  202   a , with the primary FCF device  202   a  forwarding those PLOGI accept or data traffic communications  1324  to the CNA device  214   b.    
     Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.