3750 stack member identification

[vincebenghiat]

Hello,

I  have just ordered a batch of 3750-X stackable switches. I need to create 3 stacks of four switches offline and then put them in to production later (this is the first time I am working with stacks).

I have tested this and my question is what is the easiest way to tell which switch is which. for example:

On master I set up the config and provision 3 more switches:

switch 2 provision ws-c3750x-24 (let's call this switch test2)

switch 3 provision ws-c3750x-24 (let's call this switch test3)

switch 4 provision ws-c3750x-24 (let's call this switch test4)

I then configure all the ports on those. All good so far.

Now I connect the stack physically as follows:

test1 (master)

test2

test3

test4

So test1 is physically connected to 2, 2 to 3, 3 to 4, and 4 back to 1)

Now, when I do "show switch" and it says, for example switch 2, how do I know which physical switch this is referring to? Is it test2 like I want, or is it test3 or test4? I could plug a network cable in to a port and check do "show interface status" but is there a more elegant way?

Thanks.

V.

[Reza Sharifi]

Vince,

One way to do this is to identify each switch in the stack is by assigning them priorities.  So, the master gets 15 (which is the highest) then test2 gets 12, test3 gets 10 and finally test4 gets 8. Also mark each switch physically with a tag test1, test2, etc...As for sh interface status, once you switches are stacked the first number is the switch number: example 1/0/1 is switch 1 port 1 and 2/0/1 is switch 2 port one and so on.  Remember the switches are logically one switch and you control and configure all the switches from the master.

HTH

[nkarpysh]

Hi Vince,

Adding to Reza. You can always session into each switch and check show version there thus you will have idea on what is the serial number that you can match to a physical switch. Also there is another way other than priority is to explicitly configure switch number:

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_example09186a00807811ad.shtml#number

However that might be effective for some time as after some reloads/changes that can be changed automatically and you will not hove correct picture.

So best thing I think  is to write down switch's MAC and serial and check "show switch" it shows the mac) or session into particular switch and do "sh ver" to see serial number and then match that to your database.

Hope this helps,

Nik

[vincebenghiat]

Thank you. So just to ge this straight.

"One way to do this is to identify each switch in the stack is by assigning them priorities."

If I have 4 switches in a stack with the following priorities:

test1 priority 15

test2 priority 12

test3 priority 10

test4 priority 8

then when I connect the  switches in a stack test 2 will always be switch 2 in "show switch", test3 will be switch 3 etc? This is what I thought would happen but it has not turned out that way (might be an issue with my testing though).

"Also there is another way other than priority is to explicitly configure switch number:"

The problem with this is I can only see how to REORDER the switch numbers, not to allocate them inthe first place.

I think the best way for my purpose is, as Nik said, to write down the MAC addresses and match them up once the stack is connected. Seems a bit mad but that is fine.

Many thanks to both of you for your assistance.

V.

[nkarpysh]

I see it also saying it is possible to assign particular number for switch in boot loader. I did not try that myself and unfortunately don't have switch now to try but if you have a chance  - you can try that:

bootloader switch: prompt with the command set SWITCH_NUMBER stack-member-number

If you think those answer were helpful you can rate those for others to use it later if similar question appear.

Nik