Static IP Routing, Qos and Policy Maps for the C4948

[bashan121]

Hi!

Just have some questions on IP routing for the C4948. We have to set an IP address for all of VLAN interfaces (numbering around 1500) using static route towards an upper Network, question is, How many static routes maximum can be configured for the C4948? Datasheet mentions 32,000 supported routes, is this correct?

We also have to limit the downstream bandwidth towards users for each VLAN to say 10 Mbps or 5 Mbps, we would like to check what types of bandwidth control can be configured? Can we utilize QoS and Policy maps for downstream bandwidth control? If that is possible to do (that is limit the bandwidth) using QoS and Policy Map in tandem, how many Policy maps may be configured for the C4948? Documents I've read mention Policy Maps are per interface?

I guess its a mouthful of questions, highly appreciate your help!! Thanks a lot!

Fidel Serrano

[Giuseppe Larosa]

Hello Fidel,

32,000 routes is the size of the IP routing table and of the TCAM in a multilayer switch.

You cannot expect to be able to configure 32,000 static routes on the device most of these have to be learned via dynamic routing protocol.

In some low end routers max static routes has been 700 to give a figure.

I would suggest to use a dynamic routing protocol and to consider a hierarchical address plan that allows you to represent 1,500 IP subnets with few aggregates routes.

For example:

IP subnets 192.168.x.0/24 can be summarized in one entry 192.168.0.0/16.

So in this case one entry represents 254 subnets.

2)

product overview can help

(c4948 shares documentation with C4500)

http://cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/46sg/configuration/guide/intro.html#wp1073232

Hope to help

Giuseppe

[bashan121]

Hi Giuseppe!

Bon Giorno!

Thanks very much for your helpful insight on the number of realistic Static routes that can be supported on this switch. Sharing your experience with multilayer switch is just what we needed. Appreciate the link that you provided!

Fidel Serrano