This integer sets where a given TACACS+ server entry falls in the switch's try-order (1 through 8) when it needs to authenticate a session, so a lower priority number here typically means the switch reaches for that server first. Getting this wrong can silently shift login traffic onto a server the admin intended as a backup, adding latency if that secondary server is farther away or under lower capacity. As an example, setting a local data-center TACACS+ server to priority 1 and a DR-site server to priority 2 ensures the switch only falls back to the distant server if the primary is unreachable.