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Community Member

VTP Problem

Hi all;

Today I faced a problem and I want to discuss it with you, I have 3 MLS switches ( SW1:3750, SW2:3550, SW3:3560 ) connected to each other by trunks. SW1 connected SW2 and SW2 connected to SW3. all Trunks allowed all VLANs and ( VTP version 2 , null VTP domain name all switches).

SW1 connected to PE router and SW2 & SW3 to customers.

Q1: which one should be VTP Server, and others to be transperant? best practice!!

Then I will tell you what happend with me.

Hall of Fame Super Bronze

Re: VTP Problem

If you have 'null' VTP domain, then you should be running transparent in all switches.




Re: VTP Problem

You wouldn't need any server if the other 2 are transparent , just make them all transparent.

Re: VTP Problem


I think its better for u to keep all the switches in Transparent mode as others have said.

I guess u r vlan database was changed when these switches received a update from any of the switches.



Community Member

Re: VTP Problem

Thanks alot for all suggestions.

SW1 connected to PE router and also connected Trunk to SW2 and then SW2 trunked to SW3, all the customers terminated on SW2 and SW3 (as access layer switches).

VTP domain name is null

VTP version 2

We make SW1 as a VTP server and SW2+SW3 VTP transparent.

Note; all trunk allowed all vlans

Then I add VLAN in SW3 ( customer terminated in this switch) and I add the vlan manaullay to SW1 and SW2 to pass it but the customer can't reach our services, then I make SW1 and SW2 as a VTP transparent and SW3 to be as a VTP server with add the vlan manaullay to SW1 and SW2 ----> then everythings are working fine.

So I need your help why this thing happend with me and as I know even by this way should work? , please correct me.

Re: VTP Problem

VTP has gone out of fashion, so people just make the mode transparant, but then you have to configure the required Vlans on all the switches (if you are using trunks and there is not a vlan access port for that vlan on the switch) so I still like to have a server, and make the others clients, then any vlan change you do on the server vlan gets propagated to the clients

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