3550 hardware capabilities question

[r-sinyuk]

Hi All.

Does anybody know what does "8 routed interfaces" mean in "show sdm prefer" command:

hotdog#sh sdm prefer

The current template is the default template.

The selected template optimizes the resources in

the switch to support this level of features for

8 routed interfaces and 1K VLANs.

number of unicast mac addresses: 5K

number of igmp groups: 1K

number of qos aces: 1K

number of security aces: 1K

number of unicast routes: 8K

number of multicast routes: 1K

May be it means that switch optimized for 8 L3 interfaces in hardware? But I use 39 L3 interfaces without any problems, all traffic routed in hardware because CPU load not exceed 3%.

The Understand and Configure the Switching Database Manager on Catalyst 3550 Series Switches

http://www.cisco.com/en/US/products/hw/switches/ps646/products_tech_note09186a0080094bc6.shtml

contain phrase:

"... The number of Switched Virtual Interfaces (SVIs) that is, the number of routed interfaces

is the recommended number for each platform. The software does not limit the number

of SVI ports, but as the number of ports increases, the available resources decrease. "

Which resources talking about ?

And the second question, the "sh sdm prefer" command displays info about 1K ecurity Access Control Entries, but inacl has ore than 1500 ACE:

hotdog#sh tcam inacl 1 statistics

Ingress ACL TCAM#1: Number of active labels: 17

Ingress ACL TCAM#1: Number of masks allocated: 80, available: 128

Ingress ACL TCAM#1: Number of entries allocated: 271, available: 1393

The third question: does anybody know about Cisco plans to IS-IS routing support on 3550 ?

Thank.

[vkapoor5]

Routed interfaces means SUBNET VLANs or SVI's. This command shows the RECOMMENDED(only) max number of routed interfaces for this platform according to the applied template. Actually, that purely depends on type and amount of traffic, like intervlan, bridged traffic etc. And, the resources they are taking about are of CPU and Memory. And coming your second question, "sh sdm prefer" command shows the maximum ACEs allowed for the applied template. It don't show about actual limit. For third question, no IS-IS support for 3550 at present. Cisco might be planned for next Cisco IOS releases.

[r-sinyuk]

In other words, if I have 40 routed interfaces with line speed traffic, then packets between 8 interfaces will be routed in hardware, the rest of traffic will be routed in software (via CPU)? Am I right?

[tbaranski]

I doubt it's that simple. The article you linked above is very vague about what exactly happens when more than 8 SVIs are configured, leading one to believe that the answer is complex.