Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 171)

Brocade Virtual ADX Server Load Balancing Guide 155
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Stateless TCP and UDP ports
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If client 10.161.1.88’s Web browser sent the request from TCP port 8080, and the Brocade Virtual
ADX’s hash calculation resulted in selecting real server 10.10.10.2, the packet would have the
following address values:
• Source IP: 10.161.1.88
• Source application port: 8080
• Destination IP: Real server’s IP 10.10.10.2
• Destination application port: 80
Because the client’s request contains the client’s IP address and application port, the real server
can send the packet back to the client along any valid routing path. The request does not need to
pass back through the Brocade Virtual ADX that forwarded the request. In fact, the Brocade Virtual
ADX that forwards the requests to the transparent VIP does not create session table entries for the
requests.
Because the Brocade Virtual ADX does not maintain state information for the requests for stateless
application ports, the Brocade Virtual ADX does not care whether the server response for a
stateless port passes back through the Brocade Virtual ADX on the way to the client. For a normally
configured VIP, the server’s response passes back though the Brocade Virtual ADX. For a
transparent VIP, the response does not necessarily pass back through the Brocade Virtual ADX.
NOTE
Because the Brocade Virtual ADX does not create session table entries for requests to the stateless
application port, you cannot use Brocade Virtual ADX features that use information from the session
table. For example, you cannot use source NAT, port translation, and similar features.
Configuring the stateless hash table size
You can configure the size of the stateless hash table as shown in the following:
Virtual ADX(config)#server real R1 10.10.10.1
Virtual ADX(config-rs-R1)#server stateless-hash-table-size 1024
Syntax: [no] server stateless-hash-table-size table-size
The table-size variable can be set to any of the following values: 256, 512, 1024, 2048, 4096, or
8192.
The default value is 256.
Configuring a stateless application port
To configure an application port to be stateless, enable the stateless parameter on the port in the
virtual server as shown in the following example.
Virtual ADX(config)#server real R1 10.10.10.1
Virtual ADX(config-rs-R1)#port http
Virtual ADX(config-rs-R1)#exit
Virtual ADX(config)#server real R2 10.10.11.1
Virtual ADX(config-rs-R2)#port http
Virtual ADX(config-rs-R2)#exit
Virtual ADX(config)#server virtual-name-or-ip StatelessHTTP 192.168.4.69
Virtual ADX(config-vs-StatelessHTTP)#port http stateless
Virtual ADX(config-vs-StatelessHTTP)#bind http R1 http
Virtual ADX(config-vs-StatelessHTTP)#bind http R2 http