Extreme Networks Px Series - Manual (Page 63)

Px Series Application Switch Installation and Configuration Guide 6-5
Persistence Modes
Configuring Client IP Stickiness
To enable and disable client IP persistence (stickiness), use the following commands:
[enable | disable] sticky [L4 | L7] client-ip
Client IP entries are aged out of the database in a configurable amount of time. By
default, they are deleted after 30 seconds without use. To adjust these timers, use the
following command:
config sticky client-ip timeout HH:MM:SS
The timer affects both layer 4 and layer 7. Valid values are in the range 00:00:05 (5
seconds) to 97:43:52. You can specify the value
infinity to indicate that the stickiness
should last forever.
Cookie Persistence Modes
Cookie persistence modes are layer 7 methods for establishing stickiness. When a client
accesses a web server, the web server can send the client a cookie. The cookie can be
programmed to contain many different pieces of information, including:
• The IP address of the web server
• A session identifier
• The expiration timer for the cookie
• Other information generated by the server
Each time the client sends a request to the server, the cookie is sent as part of the
transmission. Using cookie persistence modes, the Px series application switch examines
information in the cookie and uses that information to maintain the session with the
appropriate web server.
The Px series application switch supports three cookie persistence modes:
• Self-identifying cookie persistence
• Hashed cookie persistence
• Learned cookie persistence
Self-Identifying Cookie Persistence Mode
Using self-identifying cookie persistence, the web server places its real IP address in the
cookie. Figure 6-2 illustrates self-identifying cookie persistence mode.