Changing the TACACS+ Server

Use the following steps to change TACACS+ server configuration to avoid service interruption of authentication and authorization.

Unconfigure the existing primary TACACS+ server.
Note
The command disable tacacs is not required while changing TACACS+ servers.

If only a single TACACS+ server is configured, you must disable TACACS authorization (if enabled) before reconfiguring TACACS+ server:

disable tacacs-authorization

To unconfigure the existing primary TACACS+ server:

unconfigure tacacs server [primary | secondary]

Note
After this step, TACACS+ will failover to secondary server.
Configure the new primary TACACS+ server:
configure tacacs [primary | secondary] server [ipaddress | hostname] {tcp_port} client-ip ipaddress {vr vr_name}
Configure the shared-secret password for primary TACACS+ server:
configure tacacs [primary | secondary] shared-secret {encrypted} string

Note
Only after configuring shared-secret password for primary server, TACACS+ will fallback to primary server from secondary.
Unconfigure existing secondary TACACS+ server:
unconfigure tacacs server [primary | secondary]
Configure new secondary TACACS+ server:
configure tacacs [primary | secondary] server [ipaddress | hostname] {tcp_port} client-ip ipaddress {vr vr_name}
Configure shared-secret password for secondary TACACS+ server:
configure tacacs [primary | secondary] shared-secret {encrypted} string