2811 Router as a Layer3 switch

[insccisco]

Hi Guys,

I have a environment with only 1 1841 router that has 6 interfaces (2 came with the router and 4 from an HWIC 4-port card we added to the Router)

We also have a 24-port 2950 switch

Currently we have 5 VLANS and for every VLAN we connect one of the Router's interfaces to that VLAN so it can serve as the default gateway. As you know, this is not very scalable because we lose ports on the switch and interfaces on the router. We don't want to create virtual interfaces on this router.

What we want to do i if we can use a 2811 instead of the 1841 and buy a Network Module with 24 or perhaps 36 ports in it and use this setup as layer 3 switch.

Any ideas if this will be the route to go?

[insccisco]

awesome.... great knowledge Jon

thank you

[jwdoherty]

Before going with a Ethernet module within a 2811, a couple of technical points you might want to note.

Many of the Ethernet modules don't provide sufficient bandwidth for the module's backplane connection to support all of the ports at wire speed.

Not sure that any of the Ethernet modules actually do L3 on the module but instead rely on the router for L3.

If traffic forwarding is dependent on the 28xx, it doesn't have nearly the performance of most L3 switches.

You also want to look at the Catalyst 3560-8PC.

[keegan.holley]

I think you should at least consider sub-interfaces. The bandwidth constraints depend on what is connected to the vlans. For example I doubt 24 users connected to various ports could generate 100M to the uplink if you offered to pay them.