Problems Changing ASA Interface to a Trunked Port

Recently we had a team change the inside interface of one of our ASA’s to be a trunked port so we could support multiple VLANs.  To do that, we needed to move the “nameif Inside” command and IP address from the physical interface (Eth0/1) to a new subinterface (Eth0/1.4094).  In doing so I came across a few gotchas: [more]

Problem 1:

When you remove the nameif command from an interface, all associated configuration is removed from the running-config. 

Solution:

There isn’t an easy way to migrate the nameif command from one physical interface to a new one.  Once you make the change you have to reenter any configuration that included the interfaces nameif name.  The alternative is to create a new startup-configuration with the changes and reboot to that startup file.

Problem 2:

After moving the nameif command to a new sub-interface I couldn’t SSH to the device via that interface.

Solution:

Basically, the SSH daemon needs to be restarted.  I was remotely making these changes via SSH so my only option was to reboot the ASA. 

Networking Cisco ASA