Changing the TACACS+ Server

Use the following steps to change TACACS+ server configuration to avoid service interruption with respect to authentication and authorization.
  1. Unconfigure the existing primary TACACS+ server.


    After this step, TACACS+ will failover to secondary server.
  2. Configure the new primary TACACS+ server.
  3. Configure the shared-secret password for primary TACACS+ server.


    Only after configuring shared-secret password for primary server, TACACS+ will fallback to primary server from secondary.
  4. Unconfigure existing secondary TACACS+ server.
  5. Configure new secondary TACACS+ server.
  6. Configure shared-secret password for secondary TACACS+ server

To unconfigure the existing TACACS+ server, use the following command:

unconfigure tacacs server [primary | secondary]

To configure a TACACS+ server, use the following command:

configure tacacs [primary | secondary] server [ipaddress | hostname] {tcp_port} client-ip ipaddress {vr vr_name}

To configure shared-secret password for TACACS+ server, use the following command.

configure tacacs [primary | secondary] shared-secret {encrypted} string

When only a single TACACS+ server is configured, it is essential to disable tacacs-authorization(if enabled) before reconfiguring TACACS+ server.



Command disable tacacs is not required while changing TACACS+ servers. And it is recommended to disable tacacs-authorization (if enabled), before disabling TACACS+.