Layer 3 routing with 3550

Separating the 3 vlans and routing between them is pretty simple. Just make sure the command 'ip routing' is on the switch. That enables the L3 Switching. An access list on each vlan will allow/disallow traffic as you like. Each vlan interface will need its own IP address in order to pass between the Vlans.

Now, here's a very important point. If you are going to do this, you either can not use the 3550 for routing to the internet, or you need to apply policy based routing rules. So, what I would suggest is that devices on each vlan use their internet router as a default gateway, not the 3550. Each internet router will use a static route back to the other 2 vlans. Then, the 3550 only comes into play when you want to route between the vlans.

Somehow that is much clearer in my mind than it came out on the page. Let me know if that wasn't quite clear..

Hope that helps,

Jim

Hi Jim,

Thanks for helping out ,Right now I have each device in vlan 1 is configured to use there internet gateway as default gateway ,As I have understood ,if I would create a svi for each vlan and assign it an ipaddress and then how I would be able to route packtes between vlans and to internet for each vlan.

for eg vlan 1 has ip address of 10.28.250.0 /24 each device in it has default Gw set 10.28.250.1 which is there internet Gw,now if I create a svi for vlan 1 on the switch , what ip address shuld i assign to it and how do i route pacekts to internet from this gw and other vlans like vlan 2 is 10.28.249.0 /24

TIA Aman

Hey Jim,

I read through ur reply again and I will try what you have mentioned this weekend,I will try putting a static route on each of the dsl routers back to svi of a vlan and see if that works. Will keep you posted on how it goes ,Thanks again for helping out.

Aman.