[c-nsp] Problem interface

[John Bittenbender]

On 8/28/05, Skeeve Stevens <skeeve at skeeve.org> wrote:
> 
> Hey guys,
> 
>         I have a new client for whom I manage their border and BGP.  The
> router is a 7206vxr.  The router was badly setup before.. And I have
> re-written 90% of the router already.  But their network is badly setup, but
> I need some more reasons why I can pressure them to change.
> 
>         The key issue is that they run all their server - a couple of
> hundred - in layer 2 with all the servers landing on a dot1q trunk on the
> 7206vxr.
> 
> interface FastEthernet1/0.200
>  encapsulation dot1Q 200
>  ip address x.x.103.1 255.255.255.0 secondary
>  ip address x.x.104.1 255.255.255.0 secondary
>  ip address x.x.96.1 255.255.255.0 secondary
>  ip address x.x.100.1 255.255.255.0 secondary
>  ip address x.x.101.1 255.255.255.0 secondary
>  ip address x.x.102.1 255.255.255.0 secondary
>  ip address x.x.105.1 255.255.255.0 secondary
>  ip address x.x.97.1 255.255.255.0
>  no ip proxy-arp
>  no ip mroute-cache
>  no snmp trap link-status
>  no cdp enable
> 
> So essentially every server, a couple of hundred land on the router here
> with one of the above addresses being the servers default gateway.
> 
> I would like some advice from you guys in how many ways this is bad so I can
> hit them with it all and convince them to a layer 2/3 switched environment.

I don't claim to be a Cisco expert, so correct me if I'm wrong.

I think that in the case of all those secondary ip addressess they are
no longer CEF switched, but processor switched.

So, if I'm not mistaken you are eating up that poor 7206's CPU for all
packets to and from the subnets that are secondaries. - Potential to
impact routing reconvergence, throughput, management, etc.

You should tell them that there are 4096 possible VLANs and that they
aren't going away so they may as well use them.

JB