How to solve VTP domain mismatch?

How to solve VTP domain mismatch?

Comments

1. Correct the VTP domain name on the neighboring switch so it matches, to be safe I would recommend setting it to VTP transparent to reset the revision number to 0 before adding it to the domain then set it back to server or client depending on your design.
2. Disable DTP with the “switchport nonegotiate”

How do you disable DTP negotiation on both sides of the link?

There are two ways to disable DTP negotiation:

1. Configure the interface for access mode.
2. Use the switchport nonegotiate command on the interface.

What are VTP domains?

A VTP domain for a network is a set of all contiguously trunked switches with the matching VTP settings (domain name, password and VTP version). All switches in the same VTP domain share their VLAN information with each other, and a switch can participate in only one VTP management domain.

What is Switchport Nonegotiate command?

switchport nonegotiate: Prevents the interface from generating DTP frames. You can use this command only when the interface switchport mode is access or trunk. You must manually configure the neighboring interface as a trunk interface to establish a trunk link.

Does Switchport mode trunk disable DTP?

The switchport nonegotiate command disables DTP negotiation on a Layer 2 interface. This command is only accepted for interfaces that are statically configured in access or trunk mode. DTP negotiation cannot be disabled on an interface that is configured in dynamic auto or dynamic desirable mode.

Which two DTP modes negotiate building a trunk?

A trunk mode interface can also negotiate with the other side switch interface to form a trunk link between two switches. The nonegotiate mode disables sending DTP packets from an interface. “nonegotiate” mode is possible only when the interface switchport mode is “access” or “trunk”.

How do I disable VTP domain?

With VTP V1 and V2 it is not possible to completely disable VTP on Cisco switches; the best you can do is to place the switch in the VTP transparent mode. VTP V3 adds the mode off option which effectively disables VTP.

Why do we need VTP domain?

VTP enables you to create the VLAN only on a single switch. That switch can then propagate information about the VLAN to every other switch on the network and cause other switches to create it.

What does native VLAN mismatch mean?

The Cisco Native VLAN mismatch basically is saying that you have a device plugged into your Cisco device that has a different native VLAN than your switch.

Why is it a good idea to disable DTP?

If all it takes is the right DTP packet to form a trunk from an access port, an intruder can easily inject traffic into whatever VLANs are allowed on the port (by default, all of them). This configuration prevents DTP packets from being sent, effectively disabling trunk negotiation and evaluation of the VTP domain.

When should I disable DTP?

What happens when we disable DTP on an interface? When an interface in access or trunk mode has DTP disabled on it (by using the switchport nonegotiate command), it will not participate in DTP negotiation, and will not respond to incoming DTP frames. Any DTP frames that it receives will simply be ignored.

Why is dtp-5 domainmismatch unable to perform trunk negotiation?

%DTP-5-DOMAINMISMATCH: Unable to perform trunk negotiation on port Gi0/25 because of VTP domain mismatch. The reason for this was a change of VTP domain name on one switch. The thing I cannot understand is that both switches had VTP mode transparent before making this change.

Can a device complain about a VTP domain mismatch?

With the right conditions, VTP transparent mode can forward the VTP VLAN database. So, VTP transparent mode complaining about a VTP domain can make sense. On the other hand, if you have a device that supports VTP off mode, and that’s what’s active, I wouldn’t expect it to complain about a VTP domain mismatch.

Why does DTP send error message that trunking is not possible?

The DTP packets exchanged finds that the domain name mismatches and hence prints the message that trunking is not possible. To fix this issue, reconfigure the switch to ensure that the two ports that are involved in trunk negotiation belong to the same VTP domain.

What happens to MD5 digest on VTP server?

Once a name of a VLAN has been changed on the VTP server the MD5 digest will be changed. However, the MD5 digest on the client remains the same and the following message is shown: *** MD5 digest checksum mismatch on trunk: Po1 ***