I always thought the Interface VLAN number had to match the VLAN number that the interface was to belong to. However, recently I saw that it isn't in one instance. Can anyone confirm a) if interface VLAN num should = VLAN num, or b) they are mapped to each other in another way? They've always worked properly when I gave them the same number.
Confusing Example: PC<--->[L2 Switch]<---->[L2/L3 Switch] ---> Cloud
PC is connected to VLAN10 access port on L2 switch. PC IP is 192.168.200.5/24. PC gateway is 192.168.200.1.
L2 switch is connected to L2/L3 switch over trunk containing VLAN 10.
L2/L3 switch has Interface VLAN 20 with the IP 192.168.200.1.
The PC can communicate with the gateway and the rest of the network.
So, Interface VLAN 20 can be a part of VLAN 10?!?!?! I thought the numbers had to match and the SVI<->VLAN = 1:1.