VTP configuration Revision

[alwahidi22]

Hi Experts,

A---Trunk Link----?

If Switch A has 3 VLANS ( 2,3,4 ) and the default one VLAN 1 and it's configuration revision number is 3 and it's domain is Cisco.

I Added a new switch called Switch B with configuration revision number of 101 and it has VLANS(200-300) and the default VLAN 1 , it's domain is Cisco.

I want to know what will be happened for switch A VLANS , and what is the solution to avoid the problem if it happened.

Regards,

Ibrahim Alwahidi

[Edison Ortiz]

All Vlans on Switch A will be erased and replaced with the Vlans from Switch B since Switch B has the highest configuration revision number.

You need to choose which vtp domain you want to keep since you can't merge them while having different configuration numbers.

If you want to avoid this problem, you can run both switches in transparent mode and they wouldn't affect each other vtp domain.

[alwahidi22]

Thanx Edison,

If i change the domain name for switch B and then revert it to it's original domain ( Cisco) , is it work ?

Regards,

Ibrahim Alwahidi

[Edison Ortiz · Accepted solution]

Yes, it will reset the configuration revision numbering. On this case, Switch A will wipe Switch B's vtp configuration.

[alwahidi22]

Thanx Edison for your help.

Regards,

Ibrahim Alwahidi

[Amit Singh · Accepted solution]

Ibrahim,

Switch B will overwrite the Vlan database on Switch A as it has a high config revision number.

In addition you Edison's suggestion of keeping them in trasparent mode, you can try few more things:

1. Depending on which switch's Vlan you want to keep ,on the other switch change the VTP mode to transparent and back to Server, this will set the revision number to 0 and will update itself with the VTP information from the other.

2. Again depending on the switch you want to use, you can change the VTP domain name to some bogus name and change in back to domain name " cisco" as desired, this will change the domin name to 0 again.

You have to take these precautions always before introducing a new switch in the VTP enabled network otherwise it may bring the whole network in a complete halt situation.

HTH,Please rate if it does.

-amit singh

[alwahidi22]

Thanx Amit for your nice explanation.

Regards,

Ibrahim Alwahidi