[c-nsp] Question about "show sdm prefer" command output on Cat3560G

[Peter Rathlev]

On Mon, 2007-12-03 at 15:13 +0300, Alex A. Pavlenko wrote:
> Dear colleagues!
> 
> Consider simple output of "show sdm prefer" command on cat3560G
> LOP3-1#sh sdm pref
>  The current template is "desktop default" template.
>  The selected template optimizes the resources in
>  the switch to support this level of features for
>  8 routed interfaces and 1024 VLANs. 
> ...the rest is omitted
> The question is what does "8 routed interfaces" exactly mean?

As it says, with the level of features described (512 QoS ACEs and so
on) it supports 8 layer 3 interfaces. If you do not use all the
features, you can have more interfaces with no problems.

> Is it a maximum number of SVIs or routed ports that I can configure on a
> switch?

There problably is, but the limit is quite large. I lab-tested creating
600 SVIs on a C3650G and it didn't complain. Since it does hardware
forwarding you shouldn't feel any performance penalty from this. But if
you start using features like ACLs, QoS, VRFs and so on, it probably
can't handle this.

> What happens when I configure 9 or more SVIs? 

If you configure too many interfaces / features, the switch will
complain about lack of TCAM space. I haven't tried, but maybe it will
start process-switching and you wouldn't want that performance wise,
since it's designed as a hardware switch and the processer thus is
relatively slow.

Regards,
Peter Rathlev