A BIG-IP Administrator is configuring an SSH Pool with five members.

SSH (Secure Shell) operates over TCP port 22 , making the TCP health monitor the appropriate and correct choice for monitoring pool members in an SSH pool. The TCP monitor establishes a basic Layer 4 connection to each pool member on the designated port, verifying that the server is reachable and actively accepting TCP connections. A successful three-way handshake confirms the pool member is available; a failure marks it down and removes it from load balancing rotation.

The remaining monitor types are inappropriate for this use case:

UDP monitor operates at Layer 4 but uses the connectionless UDP protocol, which is incompatible with SSH since SSH exclusively uses TCP as its transport.

HTTP monitor sends a Layer 7 GET request expecting an HTTP response — irrelevant for an SSH service that does not speak the HTTP protocol.

HTTPS monitor functions identically to HTTP but over TLS — again, completely misaligned with SSH traffic and port behaviour.

For application-specific SSH validation beyond basic TCP connectivity, an external monitor or custom monitor could be used; however, TCP remains the standard and correct built-in monitor for SSH pool verification within the BIG-IP platform.