What could be a reason for VTP not functioning between two switches?

Mismatched VTP passwords can indeed prevent VTP (VLAN Trunking Protocol) from functioning effectively between two switches. VTP relies on a shared password for management and operation. If the switches do not have the same VTP password configured, they will not exchange VTP advertisements, leading to a failure in propagating VLAN information between them.

When the VTP password is set differently on the switches, even if they are in the same VTP domain and connected properly, they won’t be able to communicate. This will result in VLAN configurations not being synchronized as intended, which is critical for maintaining consistent VLAN information across the network.

Understanding the role of the VTP password is key in troubleshooting issues in VLAN propagation; thus, ensuring that all switches have the same configuration settings, including the VTP password, is essential for a successful VTP implementation between switches.