How to use the Loopback address for devices added to ACS

[chiefwfb]

Looking for the command to use the loopback address as the network ID for ACS. Is there a command you can configure on the switch/router to do this? Currently we fail authentication based off the p2p address connecting the device.

[henniae]

There is not way to tell the ACS server to use the loopback address, you will need to tell each device what address to use for TACACS. Basically a Cisco device uses the egress interface as the source address for a packet.

Add this command to each and every device that uses a loopback address

ip tacacs source-interface Loopback0

This tells the device to use whatever interface you specify as the source address for TACACS. On a switch that has multiple L3 Vlans pick one of the Vlans.