[c-nsp] Counters for null0?

Julio Arruda jarruda-cnsp at jarruda.com
Wed Aug 5 08:49:50 EDT 2009


luismi wrote:
> I just configure a router here to use it but it is quite strange because
> I can see correct traffic routed to "null", and I didn't expect to see
> that, I don't think it is correct.
> 
> #sho ip cache flow | incl Null
> Fa0/1.1       10.55.0.32      Null          208.67.222.222  11 0A2A 0035
> 1 
> Fa0/1.1       10.55.0.32      Null          208.67.222.222  11 0A26 0035
> 5 
> 
> 208.67.222.222 is the opendns server but the destination interface is
> "null"
> 
> Any idea why I see that? is that correct (I don't think so)?

Isn't all process switched/punted traffic reported as ifout == Null in 
Netflow ?

Is this traffic going via NAT ? (likely from what I see).


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