[j-nsp] L3 incompletes

[Bit Gossip]

Niels and all,
this means that:
- a unicast frame coming with a DA not in the arp table is discarded and
"L3 incompletes" incremented
- a multicast frame for a group address not subscribed is also
discarded and "L3 incompletes" incremented
Thanks,
Bit.

On Fri, 2008-06-13 at 14:41 +0200, Niels Bakker wrote:
> * 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.
>