Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 128)

112 Brocade Virtual ADX Server Load Balancing Guide
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Miscellaneous options
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Disabling port translation
By default, the Brocade Virtual ADX translates the application port number requested by the client
into the application port number you specify on the virtual server when you bind it to the real
server. For example, if you bind port 80 on a virtual server to port 8080 on a real server, the
Brocade Virtual ADX translates the application port in the client’s request from port 80 into 8080
before forwarding the request to a real server.
A few Brocade Virtual ADX configurations require that you disable translation for an application
port. For example, if you want to bind multiple virtual IP addresses to the same real server, you
must disable port translation for all but one of the virtual IP addresses, then bind the virtual IP
addresses to an alias port for the application. Disabling port translation enables the virtual IP
addresses to use the same actual port number on the real server while the Brocade Virtual ADX
collects and displays separate statistics for the alias port number associated with each virtual IP
address.
To disable translation for an application port, enter commands such as the following.
Virtual ADX(config)#server virtual-name-or-ip v1 10.157.22.1
Virtual ADX(config-vs-v1)#no port 80 translate
Syntax: [no] port tcp/udp-port translate
Traffic distribution among BPs
The Brocade Virtual ADX uses a hash algorithm to distribute traffic among barrel processors (BP). A
default algorithm and 3 optional algorithms operate on the Source or Destination IP addresses to
balance traffic among the BPs.
The default hash algorithm is “hash-crc32l”. In most situations, this setting will provide the most
effective distribution of traffic across BPs. If you find however that traffic is not being efficiently
distributed across the BPs on your Brocade Virtual ADX, you can try one of the other options.
To change the server hash algorithm from the default “hash-crc32l” to “hash-crc32u” use the
following command.
Virtual ADX(config)#server hash-crc32u
Syntax: server hash-crc32l | hash-crc32u | hash-xorl | hash-xoru
hash-crc32l: This algorithm performs CRC on the 32-bits of source IP in the forward direction and
the 32-bits of Destination IP in the reverse direction. The lower five bits of the computed result are
used to distribute traffic among BPs. This is the default setting.
hash-crc32u: This algorithm performs CRC on the 32-bits of source IP in the forward direction and
the 32-bits of Destination IP in the reverse direction. The upper five bits of the computed result are
used to distribute traffic among BPs.
hash-xorl: This algorithm performs XOR on the 32-bits of source IP in the forward direction and the
32-bits of Destination IP in the reverse direction. The lower five bits of the computed result are
used to distribute traffic among BPs.
hash-xoru: This algorithm performs XOR on the 32-bits of source IP in the forward direction and the
32-bits of Destination IP in the reverse direction. The upper five bits of the computed result are
used to distribute traffic among BPs.