ISR4331 Subinterface with VLANs at the same time

[Jens1902]

Hello from Germany,

I am trying to connect an Aruba L2 Switch to an ISR4331 that has a "NIM-ES2-4" Card inserted.

The switching card has no free ports left so I had to connect the Aruba switch to an integrated port that is not capable of being a switchport, therefore I had to use subinterfaces. If I put the gateway IP on the subinterface everything works fine, but there are other switches connected as trunks to the switched interfaces that can't reach the default gateway now, since I moved the IP from the Vlan interface to the subinterface that is connected to the Aruba switch. The subinterface have the encapsulation dot1q [vlan-id] command on it, but there seems to be no connection between the subinterface and the vlan interface (that should have the gateway IP) or am I missing something out with Subinterfaces in combination with Vlan interfaces?

Thanks in advance,

Jens

[Reza Sharifi · Accepted solution]

Hi Jens,

I don't think you can have switch vlan as well as Sub-interface at the same time for the same subnet/vlan. One solution maybe is to connect the other Aruba switch to the one that is connected to the router. This way, you keep everything on the same subnet/vlan.  The other option would be (this is if you still have integrated ports available on the router) to connect the second Aruba switch to a different port on the router, but that means you have to put that connection in a different subnet/vlan.

HTH

[Cristian David Rincon J.]

Hi Jens, 

verify if you're using DTP and try to configure de switchport in mode Trunk, not dynamic auto to check compatibily in the interface, i think is not necessary subif, but if you really need use it. 

hope solve the problem friend.