[j-nsp] L3 incompletes

[Paul Goyette]

> My 2 cents -
> 
> The most common reason for this problem is some protocol that 
> is disabled on
> the interface in question being enabled on the other to which 
> the interface
> connects. For example, OSPF might be disabled on this 
> interface but enabled
> on the other end to which this interface connects. As a result, the
> multicast updates reaching this interface would then be 
> discarded as L3
> incompletes!

No, that should result in "policed discards", not "L3 incompletes".
This commonly shows up when the neighbor is from Brand-C and has
cdp enabled.  :)

L3 incomplete means that either the L2 frame does not contain enough
data for a full L3 header (ie, the frame says "protocol IP4" but the
frame is shorter than the minimum IP4 header of 20 bytes), OR there
is a full L3 header, but there's not enough L2 data to fill the L3
datagram (ie, the L2 frame contains 100 bytes of IP4 data, but the
IP4 header says "length 512").

> 
> If this counter in incrementing at a reguar interval, it 
> might well be a
> control packet that is sent out periodically!