VTP issues, cisco 2950

[dskalish19004]

Hi Everyone 

Regarding Catalyst 2950 switches-

I have a problem with  two recently added switches, and VTP updating it's configuration revision and collection of vLans.

What I am experiencing I noticed after I added these two switches to our metro E network

All The switches on metro E are on a single domain.

The new switches do not update VTP vlans when advertised by the cluster command switch, all the others do.

one of those existing switches with the updated VTP table, need to have a vLan set to one of these two recently added, which are now set to transparent mode

I vertified that no VTP password is set on any switch.

I then created a new vLan on the command cluster switch, set in server mode

Then on the two switches that don’t accept VTP Vlan advertisements, I changed VTP to transparent mode

Then I created the same new vLans on these two switches..

The vLan did work OK on the two switches in transparent mode

The other existing switch is acting strange (with a correctly updated VTP), in that the VLan was in the table, but when my devices were connected , they could not see each other on that vLan until I set the ports to 802.1Q Trunk, instead of Static Access,

So my questions are;

Any clue as to why on these two switches in transparent mode, why when in client mode thet don’t see the new vlan information advertised?

Should I consider abandon the client/server VTP modes and put them all in transparent mode? (I have no aversion to extra steps in configuration)

When placing switches in Transparent mode, will this affect uptime in any way, and by chance would I lose any vLan information?

Hope my descriptions are clear. Thanks in advance for your review.

-Dave

[Reza Sharifi]

Hi,

Should I consider abandon the client/server VTP modes and put them all in transparent mode? (I have no aversion to extra steps in configuration)

I would, I personally don't like vtp as sometimes it can cause more headache than can help. In the newer IOS versions, you can completely disable it. I think Cisco is slowly moving away from VTP.

When placing switches in Transparent mode, will this affect uptime in any way, and by chance would I lose any vLan information?

You should not lose any vlan as the vlan data base should be intact.

HTH

[Julio E. Moisa]

Hi

The Cisco switches 2950 were manufactured a long time ago and it is already supported by Cisco, if you have created trunks and the VTP settings were configured correctly (domain, password or version) it could be a bug on the IOS.

As Reza mentioned, I recommend to use them as Transparent. 

VLAN Trunking Protocol Recommendations

VLAN Trunking Protocol (VTP) is a Cisco proprietary Layer 2 messaging protocol that manages the addition, deletion, and renaming of VLANs on a networkwide basis. Cisco's VTP simplifies administration in a switched network. VTP can be configured in three modes: server, client, and transparent.

As a best practice, deploying VTP in transparent mode for better VLAN control, security, and manageability is recommended.

Reference: http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6800-series-switches/guide-c07-733457.html

Hope it is useful

:-)