The Vlan which the SVI is for would require atleat an active port for its line protocol be come up. Assuming,GigabitEthernet0/1 is the only access or trunk port for vlan 20 and when this went down so does the SVI associated with it.
Johnlloyd_13 is partially right... VLAN 1 is a special and it has is special use (DTP, VTP, STP, CDP etc..).Connecting an access port in VLAN 1 to and access port on VLAN 20 on another switch will result in no connectivty. If it was any other vlan th...
If you want to use the line for console connectivity then, leave the default config generated for the interface Asyncx/x/x and configure you line x/x/xexample:- If you want port of the HWIC-16A to console into some cisco device, then the config shoul...