Say I have two switches, with 2 trunked ports between them. Gi1/0/1 and Gi1/0/2 on SW1, and Gi1/0/1 and Gi1/0/2 on SW2. Both trunks allow VLANs 1, 2, 3, and 4. I want to add VLAN 5. I create VLAN5 and am ready to add it to the allowed VLANs on the trunk. I run this command on the ports on SW1, but not yet on SW2:
switchport trunk allowed vlan add 5
This would create a temporary VLAN mismatch, since VLAN5 is not yet allowed on trunked ports on SW2. Here is my question:
Would this VLAN mismatch bring down the connection between SW1 and SW2?
OR
Would this simply not permit VLAN5 until all configs are set?
