topic Re: VTP server question in Switching

VTP server question

vincentgruber8 — Thu, 27 Jun 2019 17:06:33 GMT

In regards to vtp server mode, does one switch in server mode update another switch in server mode? the material states that you can create, add, or delete in this mode, but I am not finding about updates. I am curious if I had more than one switch in server mode.

Re: VTP server question

Giuseppe Larosa — Thu, 27 Jun 2019 17:16:24 GMT

Hello Vincent,

the answer is yes in VTP version 1 and 2 if the one VTP server makes a change and increase the revision number all switches in VTP domain will follow both clients and other VTP servers.

In VTP version 3, there is the concept of primary server and only the primary is allowed to make changes.

Actually in VTP version 2 even a VTP client with an higher revision number can update the whole Vlan database!!!

This is why when connecting a new switch is better to power on it isolated and to make its revision number to become zero by changing VTP domain name and or setting to VTP mode transparent and then back to VTP mode client.

Hope to help

Giuseppe

Re: VTP server question

Martin L — Thu, 27 Jun 2019 17:40:14 GMT

see
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/37e/consolidated_guide/b_37e_consolidated_3850_cg/b_37e_consolidated_3850_cg_chapter_01100111.html

Re: VTP server question

Joseph W. Doherty — Fri, 28 Jun 2019 13:37:54 GMT

"Actually in VTP version 2 even a VTP client with an higher revision number can update the whole Vlan database!!!"

I thought that's also true for version 1.(?)

Re: VTP server question

Giuseppe Larosa — Fri, 28 Jun 2019 13:44:46 GMT

Hello Joseph,

"Actually in VTP version 2 even a VTP client with an higher revision number can update the whole Vlan database!!!"

I thought that's also true for version 1.(?)

Yes it is of course true also for VTP version 1. Thanks for your correction.

Best Regards

Giuseppe