Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 187)

Brocade Virtual ADX Server Load Balancing Guide 171
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Layer 7 health checks
4
IMAP4
The Brocade Virtual ADX waits for a message from the IMAP4 server:
• If the server sends a greeting message that starts with “* OK”, The Brocade Virtual ADX sends
a Logout command to the IMAP4 port on the real server, resets the connection, and marks the
port ACTIVE.
• If the server does not send a greeting message that starts with “* OK”, the Brocade Virtual
ADX retries the health check up to the number of times configured (the default is two retries). If
the server still does not send the expected message, the Brocade Virtual ADX marks the server
port FAILED and removes the server from the load-balancing rotation for IMAP4 service.
Performed:
• Immediately following a successful Layer 4 TCP health check
• At regular intervals, if keepalive is enabled for the port
LDAP
The Brocade Virtual ADX supports both anonymous and authenticated bonding with LDAP servers.
With anonymous bonding, the Brocade Virtual ADX simply checks the format of the bind response
and marks the LDAP port as active so long as the format of the bind response is correct.
Authenticated bonding requires both the configuration of a username and password for
authentication and the configuration of a base Distinguished Name (DN) for searching the LDAP
directory. With authenticated bonding, the Brocade Virtual ADX marks the LDAP port as active only
after the completion of a successful authenticated bind and search operation.
Anonymous bonding
If a username and password are not configured, the Brocade Virtual ADX sends an anonymous
bind request to the LDAP server and waits for a reply. The bind request includes a configurable
version number, which can be 2 or 3. The default is 3.
• If the server sends a bind reply with a result code of any status (no error), the Brocade Virtual
ADX resets the connection and marks the port ACTIVE.
• If the server does not send a bind reply by the time the LDAP keepalive health check expires,
the Brocade Virtual ADX retries the health check for a user-configured number of retries (the
default is two). If the server still does not respond, the Brocade Virtual ADX marks the server
port FAILED and removes the server from the load-balancing rotation for LDAP service.