VLANs across two VTP domain work?

[ahmad82pkn]

Hi, i dont have two Layer 3 switches to test it out myself, i am not sure if it work or not. can someone confirm in light of experience/knowledge if it will or not.

I have a Layer 3Switch with VTP Domain ABC and 3 vlans gateway on it , a Tail T-switch is connected with it with same ABC VTP domain as client.All PC connected to tail switch(T-Switch) uses Gateway on Layer 3 switch.

Lets say this Layer 3 switch go down.

and i connect the tail switch with another Layer 3 Switch already up and running in network ( which has different VTP domain on it XYZ ) and i just configure SAME 3 VLANS gateway on this new Layer 3 switch as it was on Dead Layer 3 switch.

Will my Tail switch machines find this new gateway on new Layer 3 switch? or my machine will not communicate with new LAyer 3 switch gateway due to VTP domain mismatch?

Thanx in advance

[acampbell]

Hi,

If the VTP Domain names are mismatched then the trunk between the switches will fail.

The interfaces at either side of the trunk will show as up/up but no trunk frames will be passing.

If you chane your VTP mode to "transparent" on all 3 switches then it will work as per your plan.

Regards,
Alex.
Please rate useful posts.

[milan.kulik]

Hi,

switchport mode trunk

switchport nonegotiate

on both trunk ends would help too, I guess.

But you are right generally, the best way how to use VTP is not to use it at all, i.e., make all switches VTP transparent and configure proper VLANs on each of them.

BR,

Milan

[nkarpysh]

Hello,

Don't make it complicated. Configure HSRP/VRRp/GLBP on your L3 switches and use single VTP domain. In that case you can either backup one L3 by the other or even load-balance the traffic from PCs between two L3 switches.

Nik

[ahmad82pkn]

Hi Nikol i agree with you thats a good option , but dont have hardware for this for now.

if you can see attach diagram.

i was hoping if one day switch VTP ABC  go down, i could just move 3 tail switches with existing CORE6509 VTP XYZ and create vlans there.

but looks like i will need to login each tail and make them part of same VTP as well :-s

any other quick work around would be?

just checking my options in worst case scenario.

      

[milan.kulik]

Hi,

switchport mode trunk

switchport nonegotiate

should work even while each switch is in a different VTP domain.

But you need to configure those commands on both trunk sides.

And of course, the native VLAN shlud be the same.

HTH,

Milan

[ahmad82pkn]

Hi Milan,thanx alot,  i hope it works on judgment day

thank you for helping out.

hope to double check it as soon i have gears available.