adding new switch into VTP environment...

[snickered]

I just got a new switch and knew nothing about VTP. I had two switches to begin with and just followed the configurations of those. I added a trunk to carry the two VLANs that I use and added all the other ports to match that of the other switches. After trying to understand why this stuff worked I ran into VTP. It just so turns out that my previous switches are running VTP; one server and one client. I checked the mode of the switch I just added and it was added as a server! Everything is running right now but I am scared. It looks like to me that I have 2 servers and one client. Is this possible? I know I didn't enter a password for it to join the VTP domain... is that what is saving me? Here are the show vtp status outputs. The first two are my previous server-client switches and the third is the switch I just added.

VTP Version : 2

Configuration Revision : 2

Maximum VLANs supported locally : 255

Number of existing VLANs : 6

VTP Operating Mode : Server

VTP Domain Name : mydomain.com

VTP Pruning Mode : Disabled

VTP V2 Mode : Enabled

VTP Traps Generation : Disabled

MD5 digest : 0x3A 0x42 0xB3 0xA0 0x62 0xA9 0xD6 0xB4

Configuration last modified by 0.0.0.0 at 3-2-93 00:33:01

Local updater ID is 192.168.48.252 on interface Vl100 (lowest numbered VLAN interface found)

VTP Version : 2

Configuration Revision : 2

Maximum VLANs supported locally : 255

Number of existing VLANs : 6

VTP Operating Mode : Client

VTP Domain Name : mydomain.com

VTP Pruning Mode : Disabled

VTP V2 Mode : Enabled

VTP Traps Generation : Disabled

MD5 digest : 0x3A 0x42 0xB3 0xA0 0x62 0xA9 0xD6 0xB4

Configuration last modified by 0.0.0.0 at 3-2-93 00:33:01

VTP Version : 2

Configuration Revision : 2

Maximum VLANs supported locally : 255

Number of existing VLANs : 6

VTP Operating Mode : Server

VTP Domain Name : mydomain.com

VTP Pruning Mode : Disabled

VTP V2 Mode : Enabled

VTP Traps Generation : Disabled

MD5 digest : 0x3A 0x42 0xB3 0xA0 0x62 0xA9 0xD6 0xB4

Configuration last modified by 0.0.0.0 at 3-2-93 00:33:01

Local updater ID is 192.168.48.251 on interface Vl100 (lowest numbered VLAN interface found)

I know I should have this third switch in transparent mode but I need to do it so I don't cause downtime. Should I wait until after hours or does this setting not require a reload? TIA!

[mheusinger · Accepted solution]

Hi,

from a VTP point of view and depending on your requirements the third switch can be anything, i.e. server, client or transparent. Just keep in mind the functionality (in brief):

VTP server: create, modify, delete VLANs, stores config in NVRAM, advertises and synchronises to VTP advertisements in the same domain

VTP client: synchronises to VTP updates, no VLAN modification allowed, no VLAN stored in the config (client needs a server!)

VTP transparent: forwards VTP advertisement, does not sync, but allows for local VLAN adminstration

In your case you could convert the new switch to a VTP client or keep it as server for redundancy. Also have a look at the other posts regarding VTP.

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=LAN%2C%20Switching%20and%20Routing&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.1ddd48ca

For future upgrades and to avoid any bad things from ahppening I also would recommend you to read through f.e. "Adding a VTP Client Switch to a VTP Domain"

http://www.cisco.com/en/US/products/hw/switches/ps5023/products_configuration_guide_chapter09186a00804762bc.html#wp1223658

Hope this helps! Please rate all posts.

Regards, Martin

[snickered]

Thanks for your reply. A couple of questions for you.

1. The 3rd switch that I just added is in Server mode however the vlan configuration isn't the same. Is this because I didn't feed it a password for my VTP domain?

2. Can I change the 3rd switch to transparent without a network outage?

TIA.

[n-alexander · Accepted solution]

Changing the VTP mode of a switch does not require a reload.

[snickered]

Thanks for the comments fellas, you have helped a lot. Since I have two servers now which does the client get the configuration from? Or do the servers sync then give the configuration to the client? Also, why didn't I have to give the new switch a VTP domain password? It looks like it joined the VTP domain by the name but I never entered a password. Also, does trunk information carry over in a VTP domain?