Talk:Promiscuous mode

message: Inside each packet is a hardware (MAC) address. When a computer receives a particular packet, it checks the hardware address in it to see if the packet is addressed to it. If not, then the network card normally drops the packet. When in promiscuous mode, the network card doesn't drop the packet, thereby enabling it to read all packets.
I have understand that NIC checks packet against both given IP or MAC depending on protocol.
Since MAC address cannot be used to send packets to outside of local network.
So if I'm correct, this section of the article is little misleading..?
195.163.176.146 11:33, 18 April 2007 (UTC)
replies: text: No, network adapters don't check against an IP address.  If hosts A and B are not on the same LAN segment, and host A wants to send an IP packet (or a packet for any other routable protocol, such as IPX) to host B, and there's a third host, host C, which is a router that has a network adapter connected to the LAN segment host A is on and another network adapter connected to the LAN segment host B is on, host A will send that packet by sending the packet to host C, which will receive it and then send it to host B.  When the packet is sent from host A to host C, the destination IP address is that of host B, but the destination MAC address is of host C; when the packet is sent from host C to host B, the source IP address is that of host A but the source MAC address is that of host C. Guy Harris 17:51, 18 April 2007 (UTC)
thread_title: Network adapters match IP address and MAC address?

message: Modern virtualization NICs filter IP and/or MAC address
depending on the installed virtual machines and applications.
When would the term "promiscuous mode" apply to such
a NIC? In backwards-compatibility situations only?
For example, suppose a NIC is implementing a node-assisted
IP multicast. The MAC address is useless in that application.
Does that make it promiscuous? — Preceding unsigned comment added by 108.18.250.35  (talk • contribs) 17:56, 15 August 2012 (UTC)
thread_title: Modern Application?

message: In the opening paragraph (my emphasis added):
I believe this would be more accurate if it described passing traffic to the driver, network stack or sniffing application rather than to the CPU.  The CPU does do the processing, but the traffic is passed from the NIC to the driver to the network protocol stack or sniffer. Dave Braunschweig (talk) 15:44, 6 November 2012 (UTC)
replies: text: Both are accurate.  From the hardware point of view, the NIC transfers the packet data to a buffer in the CPU's memory (well, there might be other architectures, but that's the typical one) and may deliver to the CPU a "packet has arrived" or "packets have arrived" indication (e.g., a per-packet interrupt, or a per-group-of-packets interrupt, if the CPU isn't just doing time-based polling to batch packets up).  From the software point of view, a driver is signaled as a result of the indication or polling and starts processing the packet, passing it on to other software to further process. Guy Harris (talk) 18:29, 6 November 2012 (UTC)
thread_title:  NIC Passes Traffic to NIC Driver Rather than CPU 

message: The use of word CPU would be more accurate when the processor in question is specifically programmed for the purpose or is a special purpose processor. Normally the processors in such switches are general purpose processors and the processing unit is fabricated for switching purposes alone. The use of word CPU puts me to think as if processor processes the packets and NOT the software instructions that are run by processor. 
Things become worse when someone follows the link attached to CPU (central processing unit) because the link talks about general purpose processors which is completely off-topic.  — Preceding unsigned comment added by Ripunjaytripathi (talk • contribs) 14:09, 29 November 2012 (UTC)
replies: text: No.  "CPU" is a term that's been used for general-purpose processors for ages, and, in fact, that's exactly what we're talking about - a system with a processor usually running a general-purpose operating system (whether a personal computer or an "embedded" system with a general-purpose OS) and with a network adapter, wherein the software running on the CPU puts the network adapter into promiscuous mode so that unicast packets not sent to the adapter's MAC address will be received by the adapter and delivered to the CPU.  We're not talking about network processors in switches - switches are only relevant in this article because promiscuous mode doesn't, by default, help on a switched network, so you need a "mirror port" or whatever the switch vendor calls it, but that's different from promiscuous mode. Guy Harris (talk) 20:01, 29 November 2012 (UTC)
thread_title:  Use of word CPU seems misleading