VTP transparent mode and using VTP domain

[mahesh18]

                   Hi all,

Need to ask question when  using VTP transparent mode is it good idea to use VTP domain name and password?

I know for switches in transparent mode they act as independent of each other.

So need to know why we should use vtp domain  and password with transparent mode?

thanks

mahesh

[smehrnia · Accepted solution]

Hi Mahesh,

Devices in VTP transparent mode do not install updates received, but they will continue to forward them unmodified only if its Domain Name and Password matches the one localy set on the switch.

Thats why

plz Rate if it helped.

Soroush.

[Reza Sharifi · Accepted solution]

Hi Mahesh,

In addition to what Soroush already said, usually when you configure a switch in transparent mode you don't want to be part of VTP domain, so you don't configure domain name, password , etc..

I recomend staying away from VTP, specially if you have a limited number of vlans.

HTH

Reza

[BigDawgFelton · Accepted solution]

Remember if you are using vtp in your environment, remember to check revision numbers on older switches that you may be adding back into the network. A higher revision on this new switch than your current domain an it can wipe out all of your switches.

Sent from Cisco Technical Support iPhone App

[mahesh18]

hi all,

Thanks for reply.

We have remote office where we have around 6 switches and router.

My understanding is that on VTP transparent mode switch will not change its VLAN  database.

If we make all 6 switches as transparent mode then still we create vlan individually on each switch.

Transparent switch will not listen to vlan updates from nei switch.

Questions

So is this any benefit  to have vtp password and domain name  while on vtp transparent mode?

If we do not use the vtp domain and password while in  vtp transparent mode then it all the 6 switches will work ok right?

Thanks

MAhesh

[Rajeev Sharma · Accepted solution]

Hey Mahesh,

I do not see any benefit except extra configuration on switches.

If you will have all 6 switches in transparent mode, they will never hear any vtp update so nothing to forward.

HTH.

Regards,

rajeevsh.

Rate if found helpful.

[mahesh18]

Hi all,

Many thanks to all for their reply back

Regards

MAhesh

[Mark Thattazhi]

Hi Mahesh,

I know its an old post but since I went thru it i would like to share something.

Agree with what others have told about VTP transparent mode. But i would suggest not to leave the domain name blank. Not additional benefit, but if you have a monitoring server like cisco lms etc. it might show an error of Trunk Vlans Mismatch.

Mark. Thattazhi

[Kiel Martin]

Mahesh,

I know this 2 years later, but it will help others who will come across this. If you have a Transparent switch mixed with Server and Clients switches. This is your concern....... If you do not put the Transparent switch in the same domain, then it will not forward VLAN changes to other swithces.  

So Sw1(Server-CCIE Domain) <-------> Sw2(Transparent-CCIE Domain)  <-------> Sw3(Client-CCIE Domain)

The above will work because the Transparent switch is in the same domain. This means that SW3 will get any Vlan changes that are done on SW1.

Now lets look at it the other way.........
 

Sw1(Server-CCIE Domain) <-------> Sw2(Transparent-Null Domain)  <-------> Sw3(Client-CCIE Domain)

Two things are going to happen here

1) The transparent switch is not on same domain, so SW3 will never get any updates when changes to Vlans are done on SW1. So if I add one vlan to SW1, and that make the Configuration Revision increase to the value of 10, that means SW3's Revision will still be 9, and will remain that way until the issue is corrected.

2) If you are dynamically negotiating trunks, this will never happen due to the mismatch domains. Meaning that your trunks will never come up because you did not put your Transparent switch in the same domain.

Kiel Martin