Changing VTP Primary Server

[johnlloyd_13]

hi,

i'll be replacing C3850 to C9300 for the Core switch.

can someone please advise how to "demote"/remove the C3850 as VTP primary server and configure/assign the C9300 as the new VTP primary server?

C3850#sh vtp status
VTP Version capable : 1 to 3
VTP version running : 3
VTP Domain Name : CORE
VTP Pruning Mode : Disabled
VTP Traps Generation : Disabled
Device ID : 046c.9d28.1234

Feature VLAN:
--------------
VTP Operating Mode : Primary Server
Number of existing VLANs : 60
Number of existing extended VLANs : 1
Maximum VLANs supported locally : 4096
Configuration Revision : 60
Primary ID : 046c.9d28.1234
Primary Description : CSW01
MD5 digest : 0x4E 0x74 0x27 0x13 0x3A 0x49 0x12 0x34
0x58 0xC0 0xE2 0x14 0xBF 0x87 0x7B 0x56

Feature MST:
--------------
VTP Operating Mode : Primary Server
Configuration Revision : 3
Primary ID : 046c.9d28.1234
Primary Description : CSW01
MD5 digest : 0xBB 0x2F 0x2A 0xE7 0xC1 0x5E 0xC1 0xF5
0xB1 0x73 0x05 0xB8 0x95 0x18 0x12 0x34

Feature UNKNOWN:
--------------
VTP Operating Mode : Transparent

[shambhu.kumar]

VTP configuration CLI is identical in both platform. You can use same VTP configuration in 9300 what is having in 3850.

[johnlloyd_13]

hi,

i believe there's only one VTP primary server allowed in MST.

there's a temporary trunk link between old and new CSW1 while I migrate the cable/port config.

so my question again is, how do i "demote" and remove the VTP primary server config in the old CSW1?

do i just issue a "vtp mode server mst" command in the old CSW1?

or do i issue a "vtp primary force" in the new CSW1?

SW01#vtp primary mst
This system is becoming primary server for feature mst
No conflicting VTP3 devices found.
Do you want to continue? [confirm]    
SW01#
*Feb  7 03:24:06.016: %SW_VLAN-4-VTP_PRIMARY_SERVER_CHG: 003c.109f.1234 has become the primary server for the MST VTP feature

[shambhu.kumar · Accepted solution]

VTP supports having multiple VTP servers in a domain. These servers process
updates from other VTP servers just as a client does. If a VTP domain is Version
3, the primary VTP server must be set with the executive command vtp primary.

In the new switch,

9300(config)vtp domain CORE
9300(config)#vtp version 3

! same cli in other switches as well

9300#vtp primary

9300(config)#vtp mode server mst
Change the operational state of a switch from a secondary server (the default) to a primary server and advertise the configuration to the domain.

9300#vtp primary mst
This system is becoming primary server and Setting device to VTP Server mode for MST.

with force(optional)command it overwrites the configuration of any conflicting servers. If you do not enter force, you are prompted for confirmation before the takeover.

on 3850
(config)#vtp mode server mst

An identical MST region configuration will be propagated to all switches within a VTPv3 domain, and consequently they will all form a single region. As a result, there is always a one-to-one mapping between a VTPv3 domain and an MST region.

A VTP primary server updates the database information and sends updates that are honored by all devices in the system. A VTP secondary server can only back up the updated VTP configurations received from the primary server to its NVRAM.

By default, all devices come up as secondary servers. You can enter the vtp primary privileged EXEC command to specify a primary server. Primary server status is only needed for database updates when the administrator issues a takeover message in the domain.

if you are planning to keep 3850 , configure 9300 as the primary root for instance 0 and x, and the secondary root for instance y

[Giuseppe Larosa]

Hello @johnlloyd_13 ,

yes according to the configuration guide

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/16-1/configuration_guide/b_161_consolidated_3850_cg/b_161_consolidated_3850_cg_chapter_01111100.html?dtid=osscdc000283

all you need is

vtp primary

on new node.

Hope to help

Giuseppe