Cisco Support Community
Community Member

Adding a new layer of routing

I am preparing to add a layer of routing in my network.

Currently, the 2501 which connects a remote site to corporate via frame relay performs dlsw, via DLSW REMOTE-PEER statements.

On Ethernet0, there is a BRIDGE-GROUP 10 command, with the associated

BRIDGE 10 PROTOCOL IEEE later in the configuration. The Ethernet is physically connected to a 2900, which serves as a distribution switch to other 2900’s.

I plan to add a 3550, in lieu of the first 2900 switch to create multiple VLAN’s.

My question is, does the DLSW, and Bridge statements move to the 3550, where the routing for the Vlan’s will take place? I only expect the 10mb router port to handle traffic bound for the WAN.

Cisco Employee

Re: Adding a new layer of routing

No, you will still need to have a router to act as a DLSW peer endpoint. The 3550 does not have the capability to do DLSW. So, what is probably best is to create a vlan with 2 ip addresses in it which would be the ip address on 3550 and one on the ethernet interface on the 2501. Do no routing on the 2501 and instead just default-gateway to the 3550 and then dlsw on the 2501. Then put all of the devices that need SNA connectivity into the same vlan.

Community Member

Re: Adding a new layer of routing

Thanks Timothy. I may have made this more complicated than I thought. I’m not sure this is what you’re saying, but this came to me as I was reading.

I pull out the 2900 “distribution” switch, currently connected to the 2502, and install the 3550.

I place ports 1-12 into VLAN 1 which keeps all current cascaded switches in the existing network, including E0 on the 2501.

I place ports 13-24 into new VLAN 2, address it with the new ,which I place my new addressed devices and allow the 3550 to route between them keeping the switched traffic off the 2501 router port between VLAN’s?

This will enable me to keep the DLSW all as is?

Cisco Employee

Re: Adding a new layer of routing

That sounds fine as long as the IP for the DLSW can route and get to the 2501 and that depends on if you're using the ethernet interface as the dlsw peer ip address. All of the devices that need SNA connectivity would be in vlan3

If the devices that need SNA do not also need IP connectivity, then think about creating vlan 3 and making new IP address on vlan3 on the 3550 and the eth0 on the 2501 and then change the dlsw peer commands to reflect the new addressing.

CreatePlease to create content