Extreme Networks Px Series manual Configuring Cookie Stickiness

•A three-way TCP handshake is established between the Px series application switch and server 3.

•The application switch makes the following entry in its database:

	Source	Destination	Real Server
Cookie	IP Address	VIP Address	IP Address
	65.11.11.11	64.1.1.7	10.1.1.3

•The application switch forwards the first data request from the client to server 3 (E).

•Server 3 sends a cookie to the client (via the application switch) (F). The cookie contains randomly generated information that is unique for this client, such as a session identifier:

sessionID=37654

•The client sends another data request to www.buystuff.com (via the application switch).

•The application switch examines the source IP address of the client and looks for a match in the database table.

•The application switch completes the database record by entering the cookie information:

	Source	Destination	Real Server
Cookie	IP Address	VIP Address	IP Address
sessionID=37654	65.11.11.11	64.1.1.7	10.1.1.3

•Each subsequent request sent from the client to the website contains the cookie.

•The application switch examines the cookie, looks up the forwarding information in the database, and sends each request from this client to server 3.

Learned cookie persistence mode is based on the assumption that the client IP address will not change between the first and second data requests sent to the website. After the cookie is established and entered in the table, the source IP address of the client is no longer examined, and can change as frequently as required by the ISP.

Configuring Cookie Stickiness

To configure cookie persistence you must add information to the end of the pattern-rule definition for the default domain. This means that even if no domain or URL switching

6-12 Px Series Application Switch Installation and Configuration Guide