From: Curtis Phillips (phillipscurtis@xxxxxxxxxxxx)
Date: Fri Sep 01 2000 - 17:00:08 GMT-3
I think it depend on the particualar TCP/IP stack implementation.
Some stacks create a queue for the local/logical interface and treat it
exactly as they would a packet recieved and queued from a physical interface.
So, if the stack was processing input in a round-robin fashion it would read
the packet for the logical interface in sequence, along with the other
interface queues. The packet would never see the wire though and would be
written from the output queue for that logical interface to teh input queue
and passed up the stack to the process named in the proto field.
Again, this is one concept. It may be done differently in other stacks.
Curtis
Brian Hescock <bhescock@cisco.com> wrote:
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Damiem,
I assume you're referring to not being able to ping your own serial
interface but you can the ethernet interface? There's an "Open Forum"
question/answer on this on CCO, basically, the ping on the serial
interface is sent out over the interface, it doesn't answer it locally.
Brian
Roger Wang wrote:
> I sometimes wonder that myself, but I don't know the answer. What I
> do know is that it has to do with layer 2 encap types. For example,
> frame relay interfaces - if it's a point-to-point sub-interface, a
> "map" statement won't be necessary and can't (frame-relay
> interface-dlci) to ping the local interface; otherwise, you'll need a
> "map" statement to the local interface in order to ping it (packets go
> to the other end and back). The same goes to X25 encap, I
> think.HTH,Rog
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On
> Behalf Of damien
> Sent: Friday, September 01, 2000 1:19 PM
> To: ccielab@groupstudy.com
> Subject: Somebody must know the answer
>
> 3rd time to post....!!! Can anybody tell me exactly what
> happens in terms of the IP stack on the
> Router, when you ping an Ethernet local interface and a
> Serial ptp
> Interface.........i.e. the packet is generated by the Router
> to ping its
> own interface.........where exactly the packet
> goes........or software
> instructions that are carried out..........
>
>
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