Hello.
We have an addressing plan developed for accessing networking devices. Because not all devices are running in L3 mode (and some of them are L2 by design), Loopback solution cannot be used.
We have all management addresses defined as VLAN interface on the L3 switches and propgated through trunks to L2 switches connected to the L3 switch.
The problem is when there are no L2 switches connected to the L3 switch OR all L2 switches fail, then there are no UP/UP physical interfaces associated with the L2 VLAN number so the L3 VLAN interface is shut down, and the main L3 switch cannot be accessed.
I researched the material and it is required for L3 VLAN interface to synchronize to L2 VLAN, and interface comes up only when at least one interface with the mentioned VLAN is in forwarding state. In older CATOS it was possible to limit (turn off?) this synchronization. But all our devices are running new IOS.
My question is: What can i do to force VLAN interface to always stay up? Can i somehow link L2 VLAN to the loopback?
