Switch Stacking - Old WS-C3750-24PS-S with new WS-C3750V2-48PS-S

[Ramkumar P]

Need Help,

I am on to the process of stacking a new 3750V2 with the old C3750 24PS-S, As per the cisco guidance I have uploaded both the switches with the same IOS code 12.2(53) SE1, and the priority of the old switch as 15 and new one with 1(default).

When connected the stack cable from port 1 Old to port 2 New, both the switch attemtps to be a master. Please see the attached text file.

btm3750sw02#sh switch

Switch/Stack Mac Address : 0023.34ca.e100

                                           H/W   Current

Switch#  Role   Mac Address     Priority Version  State

----------------------------------------------------------

*1       Master 0023.34ca.e100     15     0       Ready

2       Member 68bd.abd4.8b80     1      0       Progressing

Above is the status after the progress.

Can anyone help on this please.

Thanks

Ramkumar

[Ivan Shirshin]

Hi Ramkumar,

Progressing status indicates that the stack master is communicating with the new switch joining the stack, so it is a normal state.  How did you determine that a switch 2 is trying to attempt to be a master and did it change Progressing status?

Kind Regards,
Ivan

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[Ramkumar P]

Yes you are right, the switches are communicating. But stacking doesn't work.

There is no change in the status,

btm3750sw02#sh switch

Switch/Stack Mac Address : 0023.34ca.e100

                                           H/W   Current

Switch#  Role   Mac Address     Priority Version  State

----------------------------------------------------------

*1       Master 0023.34ca.e100     15     0       Ready

2       Member 68bd.abd4.8b80     1      0       Progressing

Please see the output below of switch 2(new 3750V2)

Waiting for Stack Master Election...
SM: Waiting for other switches in stack to boot...
################################################################################
#######################################
SM: All possible switches in stack are booted up

POST: Inline Power Controller Tests : Begin
POST: Inline Power Controller Tests : End, Status Passed

POST: PortASIC CAM Subsystem Tests : Begin
POST: PortASIC CAM Subsystem Tests : End, Status Passed

POST: No Cable found on stack port 1

POST: PortASIC Stack Port Loopback Tests : Begin
POST: Found Stack port 1 Down
POST: Found Stack port 2 Down
POST: Skipping Stack port External loopback
POST: PortASIC Stack Port Loopback Tests : End, Status Passed

POST: PortASIC Port Loopback Tests : Begin
POST: PortASIC Port Loopback Tests : End, Status Passed

Election Complete
Switch 2 booting as Master
Waiting for Port download...Complete

[Ivan Shirshin]

Hi Ramkumar,

Check the stack cables. It is often seen when there is a problem with stack cables connection or cable failure. And as we see below, the switch stack ports are all down, so they do nto communicate to decide the master and both try to become master:

btm3750sw02#sh switch stack-ports

  Switch #    Port 1       Port 2

  --------    ------       ------

    1          Down         Down btm3750sw02#sh switch stack-ports
  Switch #    Port 1       Port 2
  --------    ------       ------
    1          Down         Down

Kind Regards,
Ivan

**Please grade this post if you find it useful.

[Ramkumar P]

Hi Ivan,

Changing the cable didn't work.

The switch is stacked as soon as i reload the old switch( i have tried reloading the new one but no luck, tooks sometime to get the dowtime for reloading the old one since it is in production ) looks like some bug.

Working fine now. Thanks a lot for your response.

[Ivan Shirshin]

Welcome, Ramkumar. Glad it works fine now.

[startx001]

Hi Ivan,

I would like to ask if can be stack WS-C3750X-24T-S and WS-C3750G-24TS-S1U  

And if can , what need to be on both switch to work in stack.

Thanks 

Kind regards

[Leo Laohoo]

You need to ensure both switches are running the same IOS and the same Feature Set (i.  e.  IP Base or IP Services, etc).  

For 3750, I would recommend you use IOS version 121.2(55)SE9.

[Ramkumar P]

Additional Information,

btm3750sw02#sh switch stack-ports summary

Switch#/  Stack   Neighbor   Cable    Link   Link   Sync      #         In
Port#     Port              Length    OK   Active   OK    Changes   Loopback
          Status                                          To LinkOK
--------  ------  --------  --------  ----  ------  ----  ---------  --------
  1/1     Down      None    50 cm     Yes    No     Yes        8        No
  1/2     Absent    None    No cable  No     No     No         7        No

Weird, The stack ports shows down but i see it communicating. Activity between the switches,

btm3750sw02#sh switch stack-ring activity

Sw  Frames sent to stack ring (approximate)
------------------------------------------------
1       895254246

Total frames sent to stack ring : 895254246

Note: these counts do not include frames sent to the ring
by certain output features, such as output SPAN and output
ACLs.

btm3750sw02#sh switch stack-ring activity

Sw  Frames sent to stack ring (approximate)
------------------------------------------------
1       895257933

Total frames sent to stack ring : 895257933

Note: these counts do not include frames sent to the ring
by certain output features, such as output SPAN and output
ACLs.

btm3750sw02#sh switch stack-ring activity

Sw  Frames sent to stack ring (approximate)
------------------------------------------------
1       895267147

Total frames sent to stack ring : 895267147

Note: these counts do not include frames sent to the ring
by certain output features, such as output SPAN and output
ACLs.

btm3750sw02#sh switch stack-ports

  Switch #    Port 1       Port 2

  --------    ------       ------

    1          Down         Down btm3750sw02#sh switch stack-ports
  Switch #    Port 1       Port 2
  --------    ------       ------
    1          Down         Down

[Leo Laohoo]

When connected the stack cable from port 1 Old to port 2 New, both the switch attemtps to be a master.

No it's not.  Switch 1 has a priority of 15 and switch 2 has a default priority of 1.

[Ramkumar P]

Hi Leo,

Even though the switch has lowest priority, itz attempting to boot as master. See the output in my reply to Ivan.

[Leo Laohoo]

POST: Found Stack port 1 Down
POST: Found Stack port 2 Down
POST: Skipping Stack port External loopback
POST: PortASIC Stack Port Loopback Tests : End, Status Passed
POST: PortASIC Port Loopback Tests : Begin
POST: PortASIC Port Loopback Tests : End, Status Passed
Election Complete
Switch 2 booting as Master

And you are right.  But do you know WHY Switch 2 bootup as a Master?  Because Stack port 1 and 2 are DOWN.  Which means it bootup as a stand-alone and wasn't a member of a stack.

[Ramkumar P]

Leo,

The switch is stacked as soon as i reload the old switch( i have tried reloading the new one but no luck, tooks sometime to get the dowtime for reloading the old one since it is in production ) looks like some bug.

Working fine now. Thanks a lot for your response.