3750 Stacking Master/Slave

[Lakeram Harrypersaud]

We have bought 2 3750 layer 3 switch with stacking capability. I will be setting up the stacking. Is there any benefit to configure one as master and the other one slave?

Any help will be apprecriated.

Thanks,

Lake

[Edison Ortiz]

If they are running same IOS features, there is no benefit - just let it run dynamically.

If one switch is running crypto version while the other is not, you would want the crypto version to be the master in order to get the encryption services.

Regards,

Edison

[Lakeram Harrypersaud]

If i don't use master/slave, do i need to give each switch it's own IP Address?

Thanks,

Lake

[Edison Ortiz · Accepted solution]

There is still a Master/Slave relationship on a stack even if there isn't any manual configuration.

The Master election process will dictate which switch will become the Stack Master.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_52_se/configuration/guide/swstack.html#wp1234264

You don't need to assign individual IP addresses per physical switch. Once they are stacked, it will be seen as one logical entity.

Regards,

Edison

[Lakeram Harrypersaud]

Thank you

[Ven Taylor · Accepted solution]

I like to control which is master & which is slave.  If you don't, you run the risk of having your switches "upside down".

When stacked, the first switch's ports show up as gig1/0/1-48.  The second switch's ports show up as gig2/0/1-48.

If you have the wrong switch set up as the "master" then this will be upside down and someone patching into it may get it wrong.  If you end up stacking more than two, this can prove difficult.

I change my switch numbers on the bench before stacking them.

The command is " switch 1 renumber 2 < enter > ".  Then reboot the switch.

After that, set the switch priority.  Command is " switch 2 priority 12  < enter > "

When I do it, I set my switch priority to 15 on the master, then switch 2 as priority 12, then switch 3 priority 10, 4 as 8, etc.  After each switch has its appropriate number and priority, I take them to the closet and stack them up.

It's a little extra work, but it make sure your switch ports are exactly as they should be.  It also doesn't confuse your wiring guys.

This way, 1 is on top and all subsequent numbers fall in line below 1.

switch 1 - gig1/0/1-48

switch 2 - gig2/0/1-48

switch 3 - gig3/0/1-48

switch 4 - gig4/0/1-48

and so on.

[Lakeram Harrypersaud]

I truly appreciate that.

Thank you very much

Lake