swapping a switch

[nethed]

Hi all,

At work i have to swap out a 3500 for a 2900 switch that is connected to a router via a trunk port. I have to do this with the least downtime so have decided to connect the new switch with the spare port on router. Steps i have outlined are:

1) configure router
2) configure new switch.
3) connect new switch.
4) move each server one at a time
5) remove old switch.

Problem:

IP addressing.
The router is running ospf.
Network management vlan is /29 and in the routing table it is /24. Am i correct then that the new switch can have a vlan in a new subnet as long as it has netmask of /29 because the router will advertise it under the /24 mask?

Also the other two vlans have the net masks of 24 and 29 but the static ip route has a mask of /24.

Any general guidline or rules to follw will be appreciated.

Thanks.

 

[Syty]

Your router is summarizing, not dynamically though.

If your router is using a x.x.x.0 /24 in the routing table, and all of the subnets are x.x.x.y /Z (where z is greater than 24, but less than 32), then it will summarize and route.

You are correct in the fact you can have another subnet, as long as it doesn't overlap any other existent subnet.

Regards,

 

[baddos]

You IP addressing shouldn't change, since your router is doing the routing.....

The 3500 and 2900 switches are layer2 only and don't do routing.

You'll need to make sure the port on the switch that connects to the router is setup the same as it was on the 3500.
You'll need to make sure the vlan databases are the same.
You'll need to have basically a duplicate config. For most of the settings, you can just copy and paste the 3500's config into the 2900's.