Replacing older 4507 with a new one, need to copy all configuration

[gevorkya99]

Hello everyone,

First post here, so please excuse any n00b mistakes...

I have a 4507(WS-C4507R) as my core switch running ver. 12.1(19r)EW, multiple VLANs and ports configured in different modes, etc.

I'm replacing this switch with another 4507(WS-C4507R+E) running ver. 15.0(1r)SG3.

I need to copy as much configuration to the new swich as possible, VLAN(VTP) info mainly as the ports and what plugs into them will be completely rewired/remapped.  I'm wondering if there's a best practices document or if someone has had to do the same and has a proven/working way of doing this.

Some items to keep in mind:

I would like the new switch to have the same IP and be able to route everything as the current one does as everything uses the current switch as the gateway and it is the Core Switch.  Copying running-config from one to another is the simple part, but that doesn't copy some of the port/interface mode configuration which is vital.

My concerns are mostly being able to configure ports the same way on the new switch, i.e. couple of ports have routers hooked up to them, need to be able to copy all the config that's needed to change those ports to the proper mode, etc. Not sure if there's some command that I don't know of to be able to gather that data.

Please let me know if you can help.

Thanks, N

[Leo Laohoo]

You didn't specify whether or not you are replacing, like-for-like, Supervisor card.

The most effective way for you to transfer the configuration from one supervisor card to another is to use the CF or SD card.

You save the config first, then you copy the startup-config and the VLAN.DAT file into the CF/SD card.  Move the card into the new supervisor card and when the card has bootup to default mode (no config), then you copy the files from the CF/SD card to the flash.

To run the config, just issue the command "copy start run".

[gevorkya99]

I was sure I'll miss some detail, sorry.

Supervisor cards are different, old one is WS-X4306-GB and new one is WS-X45-SUP7L-E

I don't think they have same card capabilities, old one is CF and new one is USB and SD I believe.

I'm not sure I want to copy the whole running or startup config as that would include port to vlan assignment(if that makes sense), so question is if i copy the vlan.dat file thru some way, will that populate/copy all the vlans from the current switch and what ports are part of the vlan?  If so, then its not really what i'm looking for.

Would setting this switch in vtp client mode and letting it generate the vlans on this switch first be a better way to go?

[rfalconer.sffcu]

What is your migration plan? Are both switches going to be up and running at the same time? Do you run VTP now?

Even with a lot of vlans, you can just copy and paste them into the new switch. It only takes a few seconds.

[gevorkya99]

Migration plan - Have the new switch configured then start physically moving devices to it.  No connection to the old switch, but both switches will be up and running untill everything is moved from one to another.

[rfalconer.sffcu]

Does the current switch have SVIs on it acting as the default gateways for clients on each vlan?

Or is it just layer 2? If it's doing L3, then what is your plan to move the SVI address from the old to new?

[gevorkya99]

yes

doing layer 3

moving all addresses to new switch

[rfalconer.sffcu]

There's no reason you can't just copy and paste the vlans you want onto the new switch. Doing this won't assign any interfaces to any particular vlans.

If you are moving layer 3 interfaces from the old switch to the new, how do you plan to have both switches online at the same time without address conflicts and/or routing issues?

I've done quite a few core migrations and connecting them together, then moving L2 and L3 in a controlled fashion works very well.

[gevorkya99]

I guess I'm looking for the best practices for this if such thing exists, but it looks like every way has pros and cons.

I'm not planning to have them connected together when those interfaces are created.

Can you elaborate more on your migration strategy?

Here's one way I was thinking of accomplishing the job:

Connect both switches

Set new one as VTP client and let it get all the vlan info

Disconnect

Set up all necessary VLAN interfaces and rest of config and set it to VTP Server

Migrate network devices from old to new

[rfalconer.sffcu]

What connects to that core switch? Is it a bunch of servers or access switches? Do you run VTP now? Are the things connected to the core single-homed or dual-homed?

A migration strategy that I've used many times is to set up the new core switch with the base configuration. If you use VTP, be careful with adding the new switch into the domain.

If not already configured, set the spanning tree priority on the old switch to something sort of low, like 12288.

Set the spanning tree priority on the new switch to something lower than the default, like 16384.

On the new switch, create the vlan interfaces in a shutdown state.

Create a trunk between the switches and verify all vlans are permitted to pass over the trunk.

Connect the switches together and make sure the trunk is up and spanning tree is acting as expected.

Start moving stuff to the new core. With the trunk up between the switches, communication will still work.

After you get everything moved, you can change the spanning tree priority on the new switch to 8192 so it becomes root for the vlans.

Then do a shut on the svi on the old switch and a no shut on the svi on the new switch. This shouldn't cause any problems. If you want a different method to move the svi, you could use HSRP to flip them. That would take some extra work to configure the existing switch with HSRP, then setting the new switch as standby, then flipping their priorities.

At this point, everything should be running through the new switch and you can shut down the old one.

[gevorkya99]

Sorry for not responding quicker...

Here's the scenario:

replacing old 4500 with single supervisor card

connected to 2 stacks of 2960s and numerous servers, has roughly 23 vlans

4500 is set as vtp server, 2960s are clients

new 4507 with dual supervisor cards is to replace this switch

the two 4500's will not be connected to each other(only temporarily to get vtp data if its the prefered method)

the goal is:

configure the new 4507 with the same IP addresses, vlans, etc. as it will be replacing the main(core) switch and will need to be the gateway for everything - do not want to have to change any of the IPs on anything

I hope this makes sense and I'm going about it in the best way possible.

My thought/plan was:

give the new switch an ip

change vtp mode to client and configure the domain, psw, etc.

trunk the 2 4500s, let it copy all vlan info

disconnect the trunk

on new 4507 change the vtp to server

configure all the vlan interfaces and rest of port specific configuration

when migrating to new switch, network cables will be unplugged from each device and new cables from new 4507 will be plugged in

will this plan work?

[rfalconer.sffcu]

It should work. While you're moving, there will be outages between different nodes since they are physically separate.

[gevorkya99]

The process I specified in my last post worked out perfect.

I'm not too sure about the rules of the forum as this is my first post, so I'm not sure if I need to mark someone's reply as the correct answer as bits and pieces of each answer made up the solution that I specified

Thanks for all the contributions

[Leo Laohoo]

You have two choices:  You can mark the post as "Answered" or you can mark them with the stars (lower left-hand corner).

You can mark anyone's post (excluding yours, of course).  You can mark all posts but you can only mark every individual's post once.