Cisco RV 325 – Losing Internet When VLAN is Enabled

When testing networking connections, don't use windows machines.

My firewall was set to allow ICMP traffic from any subnet on any domain profile yet it was still blocking the packets.

Turning the firewall off completely allowed the traffic through, so the routing is working.

Also, pings probably aren't the best way to test network connectivity.

For anyone looking to route between two VLANs on the Dell PowerConnect 5524, the commands on page 220 of the user guide are sufficient:

en
config

vlan database
vlan 100-101
exit

interface gi1/0/1
switchport access vlan 100
ip address 1.1.1.1 255.255.255.0
exit

interface gi1/0/2
switchport access vlan 101
ip address 2.1.1.1 255.255.255.0
exit

You can see the primary server (if any) in the output of show vtp status:

Primary ID                        : 0011.2233.4455
Primary Description               : primary-switch-name

If the Primary ID is 0000.0000.0000, then your current switch does not recognize any primary server, including itself. To answer your questions:

1. When you try to promote a switch to the VTP primary server role, VTP performs a sanity check to make sure no other switch on the network if already the primary, and will warn you if one is found. Either way, IOS will prompt you to proceed, so you can still back out if you're unsure. This is important, because the new primary server will cause all other VTP clients and servers to overwrite their existing VTP configuration with that of the new server. However, only switches in the same VTP domain and with the same password would be affected, and you would be able to see those with show vtp devices.

2. I think you have it mostly correct. The one part I would comment on is that the only time a primary server demotes itself to secondary status is when it rejoins the VTP domain after a reload. During normal operation, a primary server will remain the primary server unless you run vtp primary on another server.

If you have only one switch configured as the VTP server, and it is not primary, I would conclude that it was rebooted at some point, which would have caused it to demote itself. It should be safe to promote it back to primary. If you're ever unsure, back up your VLAN database (typically flash:vlan.dat on smaller platforms) before making changes, so you can switch to transparent mode and restore your VLANs quickly if you need to.

Cisco has a comprehensive document on VTP Version 3 that goes over all of this and more.