Configuring the WSM using Device Manager

LDAP health checking  

Lightweight Directory Access Protocol (LDAP) health checks enable the WSM to determine if the LDAP server is alive. LDAP versions 2 and 3 are described in RFC 1777 and RFC 2251. The LDAP health check process consists of three LDAP messages over one TCP connection:

• Bind request--The WSM first creates a TCP connection to the LDAP server on port 339, which is the default port. After the connection is established, the WSM initiates an LDAP protocol session by sending an anonymous bind request to the server.
• Bind response--On receiving the bind request, the server sends a bind response to the WSM. If the result code indicates that the server is alive, the WSM marks the server as up. Otherwise, the WSM marks the server as down even if the WSM did this because the server did not respond within the timeout window.
• Unbind request--If the server is alive, the WSM sends a request to unbind the server. This request does not require a response. It is necessary to send an unbind request as the LDAP server may crash if too many protocol sessions are active.

If the server is up, the WSM closes the TCP connection after sending an unbind request. If the server is down, the connection is torn down after a bind response, if one arrives. The connection will also be torn down if it crosses the timeout limit, regardless of the server's condition.

See also:

• Configuring LDAP health checking
• Changing the LDAP version
• About health checking
• Script-based health checking
• Direct server return health checking
• ICMP health checking
• ARP health checking
• Link health checking
• TCP health checking
• Modifying the health check interval and retries
• Application health checking
• About health checking