Cisco Nexus 3K VTP Mode Server

[johnlloyd_13]

hi,

i got a nexus 3k switch currently in production configured as VTP server.

i got a new nexus 3k which is the same HW (nexus 3048) and same version (6.0(2)U2(5)) but can't seem to configure it for VTP server.

i'm not sure how the previous admin did it. can someone advise a way on how to configure to VTP server on nexus 3k?

existing-3k# sh ver
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html
Copyright (c) 2002-2014, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained herein are owned by
other third parties and are used and distributed under license.
Some parts of this software are covered under the GNU Public
License. A copy of the license is available at
http://www.gnu.org/licenses/gpl.html.

Software
  BIOS:      version 1.2.0
  loader:    version N/A
  kickstart: version 6.0(2)U2(5)
  system:    version 6.0(2)U2(5)
  Power Sequencer Firmware:
             Module 1: version v4.4
  BIOS compile time:       08/25/2011
  kickstart image file is: bootflash:///n3000-uk9-kickstart.6.0.2.U2.5.bin
  kickstart compile time:  5/8/2014 16:00:00 [05/09/2014 03:38:26]
  system image file is:    bootflash:///n3000-uk9.6.0.2.U2.5.bin
  system compile time:     5/8/2014 16:00:00 [05/09/2014 05:30:06]

Hardware
  cisco Nexus 3048 Chassis ("48x1GE + 4x10G Supervisor")

existing-3k# sh vtp status
VTP Status Information
----------------------
VTP Version                     : 2 (capable)
Configuration Revision          : 136
Maximum VLANs supported locally : 1005
Number of existing VLANs        : 93
VTP Operating Mode              : Server

----

new-3k# sh feature | i vtp
vtp                   1         enabled

new-3k# sh ver
Cisco Nexus Operating System (NX-OS) Software
TAC support: http://www.cisco.com/tac
Documents: http://www.cisco.com/en/US/products/ps9372/tsd_products_support_series_home.html
Copyright (c) 2002-2014, Cisco Systems, Inc. All rights reserved.
The copyrights to certain works contained herein are owned by
other third parties and are used and distributed under license.
Some parts of this software are covered under the GNU Public
License. A copy of the license is available at
http://www.gnu.org/licenses/gpl.html.

Software
  BIOS:      version 1.4.0
  loader:    version N/A
  kickstart: version 6.0(2)U2(5)
  system:    version 6.0(2)U2(5)
  Power Sequencer Firmware:
             Module 1: version v4.4
  BIOS compile time:       12/09/2013
  kickstart image file is: bootflash:///n3000-uk9-kickstart.6.0.2.U2.5.bin
  kickstart compile time:  5/8/2014 16:00:00 [05/09/2014 00:38:26]
  system image file is:    bootflash:///n3000-uk9.6.0.2.U2.5.bin
  system compile time:     5/8/2014 16:00:00 [05/09/2014 02:30:06]

Hardware
  cisco Nexus 3048 Chassis ("48x1GE + 4x10G Supervisor")
  Intel(R) Celeron(R) CPU        P450 with 3785120 kB of memory.
  Processor Board ID FOC201969EK

new-3k# sh vtp status
VTP Status Information
----------------------
VTP Version                     : 2 (capable)
Configuration Revision          : 0
Maximum VLANs supported locally : 1005
Number of existing VLANs        : 7
VTP Operating Mode              : Transparent     <<< STUCK WITH TRANSPARENT PER CISCO DOC

[marce1000]

                        >....but can't seem to configure it for VTP server

 - What did you try then (which commands were executed in order to (try) to accomplish what you want, and which errors, if any , where observed ? Also check show logging ; during this 'working period' on your switch.

M.

[johnlloyd_13]

here's the error i get

new-3k# conf t
Enter configuration commands, one per line.  End with CNTL/Z.
new-3k1(config)# vtp ?
  domain    Set the name of the VTP administrative domain
  file      Set the name of the VTP file name
  password  Set the password for the VTP administrative domain
  version   Set the adminstrative domain to VTP version

new-3k(config)# vtp mode ?
                    ^
% Invalid parameter detected at '^' marker.
?

[marce1000]

 - I found this : 

 https://bst.cloudapps.cisco.com/bugsearch/bug/CSCty65147/?rfs=iqvred

 referenced in the link below. But that still doesn't explain why it is like that in the existing one.

https://supportforums.cisco.com/t5/lan-switching-and-routing/nexus-3548-switch-doesn-t-recognize-command-quot-vtp-mode-server/td-p/2529638

M.

[Andrea Testino · Accepted solution]

John,

VTP in Server or Client mode is not supported on any of our Nexus 3000 and Nexus 9000s - This is documented externally which I believe you already found.

In older versions of NX-OS such as 6.0(2)U2(5), the N3K would show server mode when you enter "no vtp mode". The CLI for configuring and de-configuring the vtp mode was hidden as the N3K only supports transparent mode. The entered command will show the mode has changed to server, but is incorrect. 

VTP server mode on the N3K was not tested by QA since it is not supported. Unfortunately, it's not on the roadmap to be supported in any future releases at this time either. Therefore, we cannot predict the behavior of the switch operating in VTP server mode. I'd recommend you stick with what is supported on the platform to avoid issues in the future that the TAC cannot troubleshoot.

Hope that helps.

[johnlloyd_13]

hi andrea,

thanks for the confirmation! it's unfortunate VTP Server mode is not supported on the Nexus 3k.

i'll just configure Transparent mode on all LAN switches.

can i ask one more thing, do u have a best practice configure for MST for Nexus 3k? should i configure MST instance 0?

[Andrea Testino]

Hi John,

Anytime! MST on the Nexus is fairly straight forward - Regarding your question about MST instance 0 - 

Instance 0 is a special instance for a region, known as the IST. The IST always exists on all ports; you cannot delete the IST, or instance 0 (it will create it on its own). By default, all VLANs are assigned to the IST. Additionally, the IST is the only STP instance that sends and receives BPDUs. 

General NX-OS MST Best Practices are found here

If your Nexus 3000 has a VPC peer, I'd go over the VPC STP Best Practices as well.

Hope that helps!