Connecting 3750 stacks

[Dwillcocks_2]

Hi,

I have an existing stack of 9 x 3750 switches (stack1).  Due to a proposed data centre move I will need to create a new stack in the new DC (Stack2) and slowly migrate all the switches over to it.  Both stacks will need to be fully active during the migration process.

I have emptied 5 of the existing 3750's and removed them from Stack 1 in preparation.  I know I can connect the two stacks using etherchannel, but that is about it.  I've been searching for any documentation, or best practices but can't find anything relevant to my scenario.

I have multiple VLANs so my questions are -

• What is the best method of connecting the two stacks initially?
• Stack 1 has an IP address for each VLAN that is the default gateway, so how would I IP the second stack VLANs?
• I believe the VLAN Db on Stack1 will be shared when I connect the stacks, what will happen when I retire stack1?

Any help or relevant links greatly appreciated.  I've posted this in the getting started forum as although I have done very basic Cisco admin this is a step up for me, if the mods think it should be moved elsewhere please do so.

Dave

[Leo Laohoo · Accepted solution]

What is the best method of connecting the two stacks initially?

If resources allow, etherchannel is a no-brainer.

Stack 1 has an IP address for each VLAN that is the default gateway, so how would I IP the second stack VLANs?

HSRP with the default gateway for each VLAN as the Virtual IP Address.

I believe the VLAN Db on Stack1 will be shared when I connect the stacks, what will happen when I retire stack1?

Depends if VTP mode, password and domain is configured correctly.

[Leo Laohoo]

Thanks for the ratings, Dave.

[Ganesh Hariharan]

Thanks for the ratings, Dave.

Hey Leo,

Congrats for the another milestone "Green Star"

Ganesh.H

[Leo Laohoo]

Thanks Ganesh.