Cisco C500s remain VTP mode Transparent

[jonathanghignoli]

We changed the Vtp domain on the Cisco 3850 VTP Server. All the Cisco switches 2924, 2950,2960, 1000 connected to it after having set the new VTP domain, in client mode have propagated the new vlans. Once the VTP Domain has been changed (despite the Vtp mode Client command), the Cisco C500s remain in Transparent Mode. If I change the old Vtp domain the Cisco C500 goes into Client mode
How do I put them in Client Mode with the new VTP Domain?

Thank you

[M02@rt37]

Hello @jonathanghignoli,

Catalyst 500 series switches don't support VTP client mode, so you will need to manually configure VLAN on them when the VTP domain changes.

Note: Cisco Catalyst 500 series switches work in VTP Transparent mode. VLAN creation, modification, or deletion done on this switch does not affect the other switches in the domain.

Source: https://www.cisco.com/c/en/us/support/docs/switches/catalyst-express-500-series-switches/70485-cat-exp-500-config.html#vlans

[jonathanghignoli]

Thanks, I saw that the C500 is in transparent, but the original vlans of the old VTP domain I should delete and renew the new vlans of the new VTP domain. How can I do?

The first time I configured the Cisco C500 switch, the vlans were taken from the Vtp server. I am attaching the screen. I did not enter the vlans described by hand, but via the vtp mode client the first time I configured the switch

[M02@rt37]

@jonathanghignoli,

Do it manually.

Since the Cisco C500 series switches operate in VTP transparent mode and do not participate in VTP domain changes, you will indeed need to manually configure the VLANs to match the new VTP domain's VLAN configuration.

[jonathanghignoli]

Ok, at the first configuration of the switch, when I go to set "VTP domain" and then "Vtp mode Client" the vlans are added. To update the vlans, can I delete vlan.dat or do I factory reset the switch and reconfigure it if I don't want to manually add the new vlans of the new vtp domain? Thanks, sorry for the inconvenience.

[M02@rt37]

@jonathanghignoli,

If you want to update the VLAN information after changing the VTP domain without manually adding the new VLANs, you can indeed delete the 'vlan.dat' file. By deleting it, the switch will rebuild its VLAN database based on the VLAN information it receives from the VTP server in the new domain.

[jonathanghignoli]

I deleted the flash:/vlan.dat, restarted the switch, but the vlans remain the same as before. Do you have any advice for me?. I would like to make this vlan update automatism work, instead of entering them by hand. There are about 30 new vlans. Thanks for your help.

[DanielP211]

Hello!

I really don't recommend VTP to anyone, and if you want to use it I would recommend vtp v3. Your network will have an outage while changing the domain and changing to vtp v3 is worth it or if you have a smaller number of switches just set them all to transparent and add the vlans on each one. 

That being said the best way to do your case of switching the vtp domain is to set everyone to vtp server then change the domains and change it back to client.

BR

[jonathanghignoli]

Cisco C500 switches only support vtp version 2

[jonathanghignoli · Accepted solution]

I solved the problem!.
The Catalyst C500 has gone into vtp client mode.
The problem was that the propagated vlans must be at most 36. The Cisco Catalyst C500 does not accept more than 36 vlans. If the VTP Server propagates more than 36 vlans the cisco catalyst c500 puts itself in vtp transparent mode. So the max 36 vlan default setting problem can't be overcome. It is necessary to make them work in client mode to propagate a number of vlans below 36.