Reassign threshold, Reassign, Threshold – Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) User Manual
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Brocade Virtual ADX Server Load Balancing Guide
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Miscellaneous health check settings
4
Basing a port’s health on the health of another port
You can configure the Brocade Virtual ADX to base the health of a port that is not well-known to the
Brocade Virtual ADX on the health of one of the following ports that are well-known to the Brocade
Virtual ADX:
•
DNS (port 53)
•
FTP (port 21). Ports 20 and 21 both are FTP ports but on the Brocade Virtual ADX, the name
“FTP” corresponds to port 21.
•
HTTP (port 80)
•
IMAP4 (port 143)
•
LDAP (port 389)
•
POP3 (port 110)
•
NNTP (port 119)
•
SMTP (port 25)
•
TELNET (port 23)
To base a port’s health on the health of another port, enter a command such as the following.
Virtual ADX(config-port-1234)#tcp keepalive port 80
Syntax: tcp | udp keepalive port TCP/UDP-portnum
The command in this example configures the Brocade Virtual ADX to base the health of port 1234
on the health of port 80 (HTTP). If the health of port 80 changes, the Brocade Virtual ADX applies
the change to port 1234.
NOTE
You cannot base the health of a port well-known to the Brocade Virtual ADX on the health of another
port, whether the port is well-known or not well-known.
Reassign threshold
The reassign threshold specifies the number of contiguous inbound TCP-SYN packets a real server
can fail to respond to before the Brocade Virtual ADX changes the application state to FAILED and
the server state to TEST. The server and application states are described in
The value of an application's reassign counter is reset to 0 when the Brocade Virtual ADX receives
a TCP SYN ACK from the application. No other type of traffic can clear this field. This reassign
counter can be seen with the show server real name_or_ip detail command where the name_or_ip
variable is the real server's ASCII name or IP address.
If a real server seems to be triggering the reassign threshold too frequently, you can increase the
reassign threshold. The reassign threshold is disabled by default. To modify the reassign threshold
to 215, enter a command such as the following:
Virtual ADX(config)#server reassign-threshold 215
Syntax: server reassign-threshold threshold-value
The range of values for the threshold-value variable is 6 through 4000. If you do not specify a
number, the Brocade Virtual ADX assigns a default threshold value of 20.