[j-nsp] L3 incompletes

[Niels Bakker]

* bit.gossip at chello.nl (Bit Gossip) [Fri 13 Jun 2008, 14:13 CEST]:
>we are experiencing a constant presence of "L3 incomplete" on a 1 Gige 
>PIC. This is ~1 every 5 mins. Any idea what can be the reason?

You didn't search the archives, did you?


>The Junos doc says "This counter increments when the incoming packet 
>fails Layer 3 (usually IPv4) checks of the header. For example, a frame 
>with less than 20 bytes of available IP header would be discarded and 
>this counter would increment."
>This means that L2 is ok so also physical layer is ok?

Ethernet interfaces in Juniper routers work in cut-through mode, 
therefore a frame that fails DA check (e.g. an unknown unicast frame 
flooded by the switch) is counted again as L3 incomplete.  This is a 
known limitation/bug/documentation incompleteness.


	-- Niels.

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