[c-nsp] Counters for null0?

[Julio Arruda]

Gert Doering wrote:
> Hi,
> 
> On Wed, Aug 05, 2009 at 11:07:09AM -0400, Julio Arruda wrote:
>>> On Wed, Aug 05, 2009 at 08:49:50AM -0400, Julio Arruda wrote:
>>>> Isn't all process switched/punted traffic reported as ifout == Null in 
>>>> Netflow ?
>>> If a given IOS version does that, it's a bug.
>>>
>>> ifout = NULL usually means "traffic dropped due to ACL or no route".
>> Traffic consumed by the router :-), that should be more specific.
>> Example, OSPF/BGP traffic, NAT traffic, some VPN traffic (tunnel 
>> interface as outbound).
> 
> I'm wondering a bit about VPN and NAT (I think this might depend very
> much on platform, but at least the software platforms should know the
> output interface).  
> 
On IPSEC, there is a great doc on www.cisco.com on the expected behaviour..

http://www.cisco.com/en/US/products/ps6601/products_white_paper09186a008022bde8.shtml

What I saw in old Catos+IOS was NOT something expected...but the 
customer changed topology, so I'm not sure if they ever opened a case 
with their support.


> BGP shows up on our 7200s as "Local" (addresses changed):
> 
> Cisco-7200>sh ip cache flow | inc 00B3
> Gi0/3.123     100.100.10.219  Local         100.100.10.200  06 8355 00B3    65 
> Gi0/1.11      100.100.10.46   Local         100.100.10.200  06 00B3 8BA5     2 
> Gi0/3.123     101.10.101.79   Local         101.10.101.65   06 E514 00B3     1 
> Gi0/1.11      100.100.10.209  Local         100.100.10.200  06 E473 00B3     1 
> Gi0/3.123     100.100.10.213  Local         100.100.10.200  06 EAD7 00B3    52 
> Gi0/3.123     101.10.101.80   Local         101.10.101.65   06 37D3 00B3     1 
> 

Interesting, how this is exported ? I seem to recall it would show as 
ifout=0, but was looking at the 'out of the box experience' :-)
And as you said, it may quite well be platform dependent...

> EIGRP is "Null", though:
> 
> Cisco-7200>sh ip cache flow | inc 224.0
> Gi0/1.11      100.100.10.111  Null          224.0.0.10      58 0000 0000    47 
> Gi0/1.11      100.100.10.118  Null          224.0.0.10      58 0000 0000    51 
> Gi0/1.11      100.100.10.117  Null          224.0.0.10      58 0000 0000    56 
> Gi0/1.11      100.100.10.114  Null          224.0.0.10      58 0000 0000    65 
> 
> gert