Brocade Virtual ADX Server Load Balancing Guide (Supporting ADX v03.1.00) - Manual (Page 173)

Brocade Virtual ADX Server Load Balancing Guide 157
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Stateless TCP and UDP ports
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The tcp/udp-port variable specifies the application port you want to make stateless.
The stateless parameter configures the port to be stateless.
The tcp | udp parameter restricts stateless operation to the specified protocol (TCP or UDP).
The no-hash parameter disables the SLB hashing mechanism for the port (and protocol, if
specified). When hashing is disabled, the Brocade Virtual ADX uses the round-robin load balancing
method to select a real server for each request.
Clearing a virtual port’s stateless hash table
You need to clear the virtual port’s stateless hash table after a specified time interval anytime a
binded real server port becomes active (from a non-active state) in order to incorporate the port
into the stateless hash table. Use the command as shown in the example:
Virtual ADX(config)#server virtual-name-or-ip StatelessDNS 192.168.4.69
Virtual ADX(config-vs-StatelessDNS)#port dns stateless clear-stateless-hash 1000
Syntax: [no] port tcp/udp-port stateless clear-stateless-hash timeout
The timeout variable is specified in number of seconds. Enter an integer from 0 to 65535.
Fragmentation support in the stateless mode
By default, fragmentation is not supported in the stateless server load balancing mode.
Consequently, fragmented packets are dropped. This feature allows you to configure fragmentation
support for a specified port in the stateless mode.
This support is necessary in situations where packets exceed the default size and need to be
fragmented. For example, DNSSEC adds security headers in the DNS response that make the
packet exceed the default packet size (512 Bytes) which causes packet fragmentation. Because of
this, DNSSEC messages will be dropped unless Fragmentation support is enabled.
Configuring fragmentation support in the stateless mode
Using this feature, stateless fragmentation support can be provided for a specified port within a
VIP. To enable fragmentation support in the stateless mode, use the following command.
Virtual ADX(config)#server virtual v1 10.10.10.1
Virtual ADX(config-vs-v1)#port dns stateless frag-support
Syntax: [no] port port-name stateless frag-support
The port-name variable specifies the port in the stateless mode that is being enabled for
fragmentation.
Feature limitations
• One real server cannot be bound to multiple VIPs even for a different service. This means that,
given a real server IP, there is only one VIP that is bound to this real server.
• Fragmented pass-through traffic is not supported.
• For L7 switching for a different port under the same VIP, Brocade highly recommends using
another VIP.