Source: https://patents.google.com/patent/US20040255154?oq=6016038
Timestamp: 2018-03-20 08:24:42
Document Index: 563796127

Matched Legal Cases: ['art 300', 'art 300', 'art 300', 'art 300', 'art 400', 'art 400', 'art 400', 'art 500', 'art 500', 'art 500', 'art 500']

US20040255154A1 - Multiple tiered network security system, method and apparatus - Google Patents
US20040255154A1
US20040255154A1 US10458628 US45862803A US2004255154A1 US 20040255154 A1 US20040255154 A1 US 20040255154A1 US 10458628 US10458628 US 10458628 US 45862803 A US45862803 A US 45862803A US 2004255154 A1 US2004255154 A1 US 2004255154A1
US10458628
For wired networks, recent security solutions from network vendors have involved pushing authentication functions out to the layer 2 port, such as to a layer 2 switch. One such solution involves authenticating the physical, or Media Access Control (MAC), address of a device coupled to the port of a layer 2 switch. Another solution involves enabling the switch to perform user authentication in accordance with protocols defined by the IEEE 802.1x standard. A further solution builds on the 802.1x protocol to dynamically assign the user to a Virtual Local Area Network or “VLAN” (as defined in accordance with the IEEE 802.1q standard) based on their identity, wherein the assignment to a particular VLAN may be premised on security considerations. However, a majority of conventional switches do not provide the ability to implement all of these security features in a single network device.
A product marketed by Cisco Systems, Inc. of San Jose, Calif., designated the Catalyst 3550 Multilayer Switch, apparently provides a combination of the foregoing security features. However, the combination of features is only provided in a multiple host (“multi-host”) configuration, in which one or more computing devices are coupled to a single port of the switch via a central computing device. Furthermore, the 802.1x authentication is always performed prior to physical (MAC) address authentication in the Cisco product. Thus, when a computing device is coupled to a port of the Cisco switch, local resources (e.g., switch resources necessary to perform 802.1x authentication and, optionally, dynamic VLAN assignment) as well as network resources (e.g., communication between the switch and an authentication server) will always be expended to authenticate the user, prior to determining whether or not the physical (MAC) address of the device is valid. This results in a waste of such resources in the case where the device has an unauthorized MAC address.
The present invention is directed to a network security system, method and apparatus that substantially obviates one or more of the problems and disadvantages of the related art.
In particular, the present invention is directed to a network device, such as a network switch, that implements a multiple key, multiple tiered system and method for controlling access to a data communications network in both a single host and multi-host environment. The system and method provide a first level of security that comprises authentication of the physical (MAC) address of a user device coupled to a port of the network device, such as a network switch, a second level of security that comprises authentication of a user of the user device if the first level of security is passed, such as authentication in accordance with the IEEE 802.1x standard, and a third level of security that comprises dynamic assignment of the port to a particular VLAN based on the identity of the user if the second level of security is passed.
The present invention provides improved network security as compared to conventional solutions, since it authenticates both the user device and the user. Moreover, the present invention provides network security in a manner more efficient than conventional solutions, since it performs physical (MAC) address authentication of a user device prior to performing the more resource-intensive step of performing user authentication, such as user authentication in accordance with a protocol defined by the IEEE 802.1x standard.
In accordance with one embodiment of the present invention, an apparatus for providing network security is provided. The apparatus includes a plurality of input ports and a switching fabric for routing data received on the plurality of input ports to at least one output port. The apparatus also includes control logic adapted to authenticate a physical address of a device coupled to one of the plurality of input ports and to authenticate user information provided by a user of the device only if the physical address is valid. Additionally, the control logic may be further adapted to assign the particular input port to a virtual local area network (VLAN) associated with the user information if the user information is valid. In an embodiment, the particular input port is assigned to the VLAN only if the apparatus is configured to support the specified VLAN.
In an alternate embodiment of the present invention, a method for providing network security is provided. The method includes authenticating a physical address of a device coupled to a port of a network switch, and authenticating user information provided by a user of the device only if the physical address is valid. The method may additionally include assigning the port to a virtual local area network (VLAN) associated with the user information only if the user information is valid. In an embodiment, the method further includes assigning the port only if the switch is configured to support the specified VLAN.
In another embodiment of the present invention, a multiple tiered network security system is provided. The system includes a data communications network, a network switch coupled to the data communications network, and a user device coupled to a port of the network switch. The network switch is adapted to authenticate a physical address of the user device and to authenticate user information provided by a user of the user device only if the physical address is valid. Additionally, the network switch may be further adapted to assign the port to a virtual local area network (VLAN) associated with the user information only if the user information is valid. In an embodiment, the network switch only assigns the port if the switch is configured to support the specified VLAN.
[0016]FIG. 1 depicts the basic elements of a multiple tiered network security system in accordance with an embodiment of the present invention.
[0017]FIG. 2 depicts an exemplary high-level architecture of a network switch in accordance with an embodiment of the present invention.
[0018]FIG. 3 illustrates a flowchart of a multiple tiered network security method in accordance with an embodiment of the present invention.
[0019]FIG. 4 illustrates a flowchart of a method for enabling physical address authentication of a device coupled to a data communications network in accordance with an embodiment of the present invention.
[0020]FIG. 5 illustrates a flowchart of a method for performing user authentication and dynamic VLAN assignment in accordance with an embodiment of the present invention.
[0021]FIG. 6 depicts a multiple tiered network security system that accommodates a plurality of user devices in a multi-host configuration in accordance with an embodiment of the present invention.
The present invention is directed to a multiple key, multiple tiered network security system, method and apparatus. The system, method and apparatus provides at least three levels of security. The first level comprises physical MAC address authentication of a device being attached to a network, such as a device being coupled to a port of a network switch. The second level comprises authentication of the user of the device, such as authentication in accordance with the IEEE 802.1x standard. The third level comprises dynamic assignment of the port to a particular VLAN based on the identity of the user. Failure to pass a lower security level results in a denial of access to subsequent levels of authentication.
B. Multiple Tiered Security System, Method and Apparatus in
[0027]FIG. 1 depicts the basic elements of a multiple tiered network security system 100 in accordance with an embodiment of the present invention. As shown in FIG. 1, system 100 comprises a data communications network 104, a network switch 102 and an authentication server 106 each of which is communicatively coupled to data communications network 104, and a user device 108 communicatively coupled to network switch 102.
Data communications network 104 comprises a plurality of network nodes interconnected via a wired and/or wireless medium, wherein each node consists of a device capable of transmitting or receiving data over data communications network 104. In the embodiment described herein, data communications network 104 comprises a conventional local area network (“LAN”) that employs an Ethernet communication protocol in accordance with the IEEE 802.3 standard for data link and physical layer functions. However, the invention is not so limited, and data communications network 104 may comprise other types of networks, including but not limited to a wide area network (“WAN”), and other types of communication protocols, including but not limited to ATM, token ring, ARCNET, or FDDI (Fiber Distributed Data Interface) protocols.
Network switch 102 is a device that comprises a plurality of ports for communicatively interconnecting network devices to each other and to data communications network 104. Network switch 102 is configured to channel data units, such as data packets or frames, between any two devices that are attached to it up to its maximum number of ports. In terms of the International Standards Organization's Open Systems Interconnection (OSI) model, network switch 102 performs layer 2, or data link layer, functions. In particular, network switch 102 examines each received data unit and, based on a destination address included therein, determines which network device the data unit is intended for and switches it out toward that device. In the embodiment described herein, the destination address comprises a physical or Media Access Control (MAC) address of a destination device.
[0030]FIG. 2 depicts an exemplary high-level architecture of network switch 102 in accordance with an embodiment of the present invention. As shown in FIG. 2, network switch 102 comprises a plurality of input ports, 204 a through 204 n, that are coupled to a plurality of output ports, 206 a through 206 n, via a switching fabric 202. Network switch 102 also includes control logic 208 for controlling various aspects of switch operation and a user interface 210 to facilitate communication with control logic 208. User interface 210 provides a means for a user, such as a system administrator, to reconfigure the switch and adjust operating parameters.
In operation, data units (e.g, packets or frames) are received and optionally buffered on one or more of input ports 204 a through 204 n. Control logic 208 schedules the serving of data units received by input ports 204 a through 204 n in accordance with a predetermined scheduling algorithm. Data units are then served to switching fabric 202, which routes them to the appropriate output port 206 a through 206 n based on, for example, the destination address of the data unit. Output ports 206 a through 206 n receive and optionally buffer data units from switching fabric 202, and then transmit them on to a destination device. In accordance with an embodiment of the present invention, network switch 102 may also include logic for performing routing functions (layer 3 or network layer functions in OSI).
With further reference to FIG. 1, a user device 108 is shown connected to one of the ports of network switch 102. User device 108 may comprise a personal computer (PC), laptop computer, Voice Over Internet Protocol (VOIP) phone, or any other device capable of transmitting or receiving data over a data communications network, such as data communications network 104. As described in more detail herein, the security features of the present invention are particularly useful in the instance where user device 108 is highly portable, and thus may be readily moved from one point of network access to another.
[0034]FIG. 3 illustrates a flowchart 300 of a multiple tiered network security method in accordance with an embodiment of the present invention. The invention, however, is not limited to the description provided by the flowchart 300. Rather, it will be apparent to persons skilled in the relevant art(s) from the teachings provided herein that other functional flows are within the scope and spirit of the present invention. Flowchart 300 will be described with continued reference to example system 100 described above in reference to FIG. 1. The invention, however, is not limited to that embodiment.
The method of flowchart 300 begins at step 302, in which user device 108 is coupled to a port of network switch 102. Coupling user device 108 to a port of network switch may comprise, for example, coupling user device 108 to an RJ-45 connector, which is in turn wired to a port of network switch 102.
At step 304, network switch 102 performs a physical (MAC) address authentication of user device 108. As will be described in more detail herein, network switch 102 performs this step by comparing a MAC address of user device 108 with a limited number of “secure” MAC addresses that are stored by network switch 102. As shown at step 306, if packets received from user device 108 have a source MAC address that does not match any of the secure addresses, then the protocol proceeds to step 308, in which network switch 102 either drops the packets or, alternately, disables the port entirely, thereby terminating the security protocol. In a further embodiment of the present invention, network switch 102 can also re-direct the packets to a network destination other than their originally intended destination based on the detection of an invalid source MAC address.
At step 310, network switch 102 authenticates a user of user device 108 based upon credentials provided by the user. As will be discussed in more detail herein, this step entails performing user authentication in accordance with the IEEE 802.1x standard, and involves sending the user credentials in a request message to authentication server 106 and receiving an accept or reject message in return, the accept or reject message indicating whether the user is valid. As shown at step 312, if the user is not valid, then the security protocol proceeds to step 314, in which network switch 102 blocks all traffic on the port except for the reception or transmission of 802.1x control packets on the port. However, as also shown at step 312, if the user is valid, then the security protocol proceeds to step 316.
At step 316, network switch 102 determines whether or not the user is associated with a VLAN supported by the switch. As will be discussed in more detail herein, this step entails determining whether a VLAN identifier (ID) or a VLAN Name was returned as part of the accept message from authentication server 106. If the user is not associated with a VLAN supported by network switch 102, the port to which user device 108 is coupled is (or remains) assigned to a port default VLAN and all traffic on the port is blocked except for the reception or transmission of 802.1x control packets, as shown at step 318. If, however, the user is associated with a VLAN supported by network switch 102, then network switch 102 assigns the port to the specified VLAN and begins processing packets from user device 108, as shown at step 320.
With reference to the exemplary switch embodiment of FIG. 2, the security functions performed by network switch 102, as described above, are performed by control logic 208. As will be appreciated by persons skilled in the art, such functions may be implemented in hardware, software or a combination thereof.
As discussed above, network switch 102 is adapted to perform a physical (MAC) address authentication of a user device that is coupled to one of its ports. In particular, network switch 102 is adapted to store a limited number of “secure” MAC addresses for each port. A port will forward only packets with source MAC addresses that match its secure addresses. In an embodiment, the secure MAC addresses are specified manually by a system administrator. In an alternate embodiment, network switch 102 learns the secure MAC addresses automatically. If a port receives a packet having a source MAC address that is different from any of the secure learned addresses, a security violation occurs.
With reference to the embodiment of network switch 102 depicted in FIG. 2, secure addresses for each input port 204 a through 204 n are stored in a local memory assigned to each port. Alternately, secure addresses are stored in a shared global memory, or in a combination of local and global memory.
In an embodiment, when a security violation occurs, network switch 102 generates an entry to a system log and an SNMP (Simple Network Management Protocol) trap. In addition, network switch 102 takes one of two actions as configured by a system administrator: it either drops packets from the violating address or disables the port altogether for a specified amount of time.
In a further embodiment of the present invention, a system administrator can configure network switch 102 to re-direct packets received from the violating address to a different network destination than that originally intended. Network switch 102 may achieve this by altering the packet headers. For example, network switch 102 may alter a destination address of the packet headers. Alternately, the re-direction may be achieved by generating new packets with identical data payloads but having different packet headers. As will be appreciated by persons skilled in the art, the decision to configure network switch 102 to re-direct traffic from a violating address may be premised on the resulting burden to network switch 102 in handling traffic from that address.
[0046]FIG. 4 illustrates a flowchart 400 of a method for enabling physical address authentication of a device coupled to a data communications network in accordance with an embodiment of the present invention. In particular, flowchart 400 represents steps performed by a system administrator in order to configure a network switch to perform physical address authentication in accordance with an embodiment of the invention. The invention, however, is not limited to the description provided by the flowchart 400. Rather, it will be apparent to persons skilled in the relevant art(s) from the teachings provided herein that other functional flows are within the scope and spirit of the present invention.
At step 402, the system administrator enables the MAC address authentication feature for one or more ports of the network switch. In an embodiment, the security feature is disabled on all ports by default, and a system administrator can enable or disable the feature globally on all ports at once or on individual ports.
At step 404, the system administrator sets a maximum number of secure MAC addresses for a port. In an embodiment, the network switch utilizes a concept of local and global “resources” to determine how many MAC addresses can be secured on each port. In this context, “resource” refers to the ability to store one secure MAC address entry. For example, each interface may be allocated 64 local resources and additional global resources may be shared among all the interfaces on the switch.
At step 406, the system administrator sets an age timer for the MAC address authentication feature. In an embodiment, secure MAC addresses are not flushed when a port is disabled and brought up again. Rather, based on how the switch is configured by the system administrator, the secure addresses can be kept secure permanently, or can be configured to age out, at which time they are no longer secure. For example, in an embodiment, the stored MAC addresses stay secure indefinitely by default, and the system administrator can optionally configure the device to age out secure MAC addresses after a specified amount of time.
At step 408, the system administrator specifies secure MAC addresses for a port. Alternately, the switch can be configured to automatically “learn” secure MAC addresses by storing the MAC addresses of devices coupled to the port up to the maximum number of secure addresses for the port. These stored MAC addresses are then used as the secure addresses for authentication purposes.
At step 410, the system administrator optionally configures the switch to automatically save the list of secure MAC addresses to a startup-configuration (“startup-config”) file at specified intervals, thus allowing addresses to be kept secure across system restarts. For example, learned secure MAC addresses can be automatically saved every twenty minutes. The startup-config file is stored in switch memory. In an embodiment, by default, secure MAC addresses are not automatically saved to a startup-config file.
At step 412, the system administrator specifies the action taken when a security violation occurs. In the case where the system administrator has specified the secure MAC addresses for the port, a security violation occurs when the port receives a packet with a source MAC address that is different than any of the secure MAC addresses. In the case where the port is configured to “learn” secure MAC addresses, a security violation occurs when the maximum number of secure MAC addresses has already been reached, and the port receives a packet with a source MAC address that is different than any of the secure MAC addresses. In an embodiment, the system administrator configures the switch to take one of two actions when a security violation occurs: either drop packets from the violating address or disable the port altogether for a specified amount of time.
D. User Authentication and Dynamic VLAN Assignment in Accordance with an Embodiment of the Present Invention
As discussed above, network switch 102 is further adapted to perform user authentication if user device 108 has a valid physical (MAC) address. In an embodiment, user authentication is performed in accordance with the IEEE 802.1x standard. As will be appreciated by persons skilled in the art, the 802.1x standard utilizes the Extensible Authentication Protocol (EAP) for message exchange during the authentication process.
In accordance with the embodiment of the invention described in reference to FIG. 1, and with reference to the 802.1x protocol described above, the user of user device 108 is the supplicant, network switch 102 is the authenticator, and authentication server 106 is the authentication server. In an embodiment, authentication server 106 comprises a server that uses the Remote Authentication Dial-In User Service (RADIUS) as described in RFC 2865, and may therefore be referred to as a RADIUS server.
In further accordance with an embodiment of the present invention, authentication server 106 provides a VLAN identifier (ID) and associated information to network switch 102 as part of the message granting authorization to a particular user. The VLAN ID is included in an access profile for the user, which is configured by a network administrator and maintained in a database by authentication server 106. Network switch 102 is adapted to determine if the VLAN associated with the VLAN ID is available on the switch, and, if so, to dynamically assign the port to which user device 108 is coupled to that particular VLAN.
[0059]FIG. 5 illustrates a flowchart 500 of a method for performing user authentication and dynamic VLAN assignment in accordance with an embodiment of the present invention. The invention, however, is not limited to the description provided by the flowchart 500. Rather, it will be apparent to persons skilled in the relevant art(s) from the teachings provided herein that other functional flows are within the scope and spirit of the present invention. Flowchart 500 will be described with continued reference to example system 100 described above in reference to FIG. 1. The invention, however, is not limited to that embodiment.
The method of flowchart 500 begins at step 502, in which user device 108 attempts to access data communications network 104 via network switch 102. In response, network switch 102 places 802.1x client software on user device 108 into an unauthorized state that permits the client software to send only an EAP start message, as shown at step 504. Network switch 102 also returns an EAP message to user device 108 requesting the identity of the user, as shown at step 506.
At step 508, the user of user device 108 inputs identity information or credentials, such as a user name and password, into user device 108 that are returned to network switch 102. Network switch 102 then generates an authentication call which forwards the user credentials to authentication server 106, as shown at step 510, and authentication server 106 performs an algorithm to authenticate the user based on the user credentials, as shown at step 512.
At step 514, authentication server 106 returns either an accept or reject message back to network switch 102. As shown at step 516, if authentication server 106 sends a reject message back to network switch 102, the protocol proceeds to step 518. At step 518, network switch 102 blocks all traffic on the port except for the reception or transmission of 802.1x control packets (e.g., EAPOL packets) on the port.
However, if authentication server 106 sends an accept message back to network switch 102, then the protocol proceeds to step 520. At step 520, network switch 102 parses the accept message to determine if a VLAN ID and associated information has been provided for the user. In the embodiment described herein, authentication server 106 provides three tunnel attributes as part of a RADIUS Access-Accept message for dynamic VLAN assignment. The following tunnel attributes are used:
Tunnel-Private-Group-ID=VLAN ID
The VLAN ID may comprise 12 bits, taking a value between one and 4094, inclusive. The VLAN ID is included in an access profile for the user, which is configured by a network administrator and maintained in a database by authentication server 106. In an alternate embodiment, a VLAN Name, which comprises a text field, is used instead of a VLAN ID for associating the user with a particular VLAN.
The VLAN assignment controls which nodes the user will have access to on the network (e.g., only nodes that are members of the same VLAN) and is primarily used to differentiate broadcast domains. A VLAN ID may be assigned to a user based on security considerations. For example, a user with a low security clearance may be assigned to a VLAN that has been defined to limit access to information available via data communications network 104.
If a VLAN ID and associated information necessary for dynamic VLAN assignment are not provided with the accept message, network switch 102 assigns the port to a port default VLAN and then accepts packets from user device 108, as shown at step 522.
However, if the appropriate information, including the VLAN ID, is provided, network switch 102 determines if the VLAN ID identifies a valid VLAN for network switch 102, as shown at step 524. In an embodiment, network switch 102 performs this step by comparing the VLAN ID from the accept message with a stored list of valid VLAN IDs for network switch 102.
If network switch 102 does not support the VLAN identified by the VLAN ID, network switch 102 assigns the port to a port default VLAN (or the port remains assigned to the port default VLAN, if already so configured) and all traffic on the port is blocked except for the reception or transmission of 802.1x control packets, as shown at step 526. If network switch 102 does support the VLAN identified by the VLAN ID, then network switch 102 assigns the port to that VLAN and then accepts packets from user device 102 for processing, as shown at step 528. In an embodiment, once a port is assigned to a VLAN, it remains dedicated to the VLAN until such time as a system administrator reassigns the port.
Performing the above-described user authentication protocol after performing physical (MAC) address authentication of user device 108 provides enhanced security when network switch 102 is operating in a mode in which secure MAC addresses can be “learned.” As discussed in Section C, above, network switch 102 can be configured to automatically “learn” secure MAC addresses by storing the MAC addresses of devices coupled to a port up to the maximum number of secure addresses for the port. By necessity, this feature exposes the port to unauthorized devices. Consequently, the subsequent performance of user authentication operates to minimize the security risk associated with this feature.
The multiple tiered security protocol described above may be advantageously implemented in both single host and multiple host (multi-host) environments. FIG. 1 depicts a single host environment, as only a single user device 108 is coupled to a port of network switch 102. FIG. 6 depicts an alternate embodiment of the present invention that accommodates a plurality of user devices in a multi-host configuration. In particular, FIG. 6 a multiple tiered network security system 600 that comprises a data communications network 104, a network switch 602 and an authentication server 106 each of which is communicatively coupled to data communications network 104. A central user device 604 is coupled to network switch 602 and a plurality of additional user devices 606 a through 606 n are coupled to network switch 602 via central user device 604 in a multi-host configuration.
The multiple tiered security protocol described above may be advantageously implemented in system 600 in a variety of ways. For example, network switch 602 may perform physical (MAC) address authentication of central user device 604 only, and then authenticate the users of all the user devices if it determines that central user device 604 has a valid MAC address. If central user device 604 has an invalid MAC address, then the port may be closed to all user devices. Alternately, network switch 602 may perform physical (MAC) address validation of each of the user devices prior to authenticating their users. In this case, network switch 102 can selectively accept packets from user devices having valid MAC addresses while dropping packets from user devices having invalid MAC addresses.
US10458628 2003-06-11 2003-06-11 Multiple tiered network security system, method and apparatus Abandoned US20040255154A1 (en)
US10458628 US20040255154A1 (en) 2003-06-11 2003-06-11 Multiple tiered network security system, method and apparatus
US20040255154A1 true true US20040255154A1 (en) 2004-12-16
ID=33510619
US10458628 Abandoned US20040255154A1 (en) 2003-06-11 2003-06-11 Multiple tiered network security system, method and apparatus
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