Example of configuration for N7K with redundant Tacacs servers
tacacs+ distribute tacacs-server key 7 "xxxxxxxx" ip tacacs source-interface mgmt0 tacacs-server host x.x.x.x tacacs-server host y.y.y.y tacacs+ commit aaa group server tacacs+ TACACS+Server server x.x.x.x server y.y.y.y
aaa authentication login default group TACACS+Server aaa authorization commands default group TACACS+Server local aaa accounting default group TACACS+Server