[nsp] PPS Interface Counters

Ryan O'Connell ryan at complicity.co.uk
Tue Jun 22 08:48:55 EDT 2004


Lawrence Wong wrote:

>How about packets which are blocked during DoS/DDoS
>attacks? Would this break the calculation as well?
>Since you could see 10,000 pps on one interface that
>doesn't go anywhere but is taken into account when
>adding things up.
>  
>

Well, Null0 has counters on it so I guess if you're routing a [D]DoS to 
Null0 it'll still be accounted for as long as you check there. I've 
never seen the input/output rate counters on Null0 ever read anything 
other than 0, but then I've always been too busy during a serious DDoS 
to look. :-) If you're blocking with ACLs or some other method, I guess 
this would break the calculation.

>Does the OID which you mention earlier take into
>account all packets that are forwarded (aka work done
>by router) or is it also limited to normal & unicast?
>  
>

I don't know for certain, but I suspect it counts every packet that 
enters the router exactly once regardless of the number of times it's 
subsequently forwarded out of the router. (Zero, one or more)

-- 
         Ryan O'Connell - CCIE #8174

I'm not losing my mind, no I'm not changing my lines,
I'm just learning new things with the passage of time



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