Extreme Networks Px Series manual 4Learned cookie persistence mode

Persistence Modes

Unlike self-identifying cookie persistence and hashed cookie persistence, learned cookie persistence does not require the website administrator to make any changes to the website. Learned cookie persistence is a best-effort persistence mode that creates a short-term stickiness between the client and the web server.

Figure 6-4 illustrates learned cookie persistence mode.

			Server 1
			10.1.1.1
A	64.1.1.7	www.buystuff.com
	B
E		C
Client	F		Server 2
65.11.11.11		D	10.1.1.2
		F
		E
		Cookie:
	sessionID=37654
			Server 3
			10.1.1.3
			WS_004

Figure 6-4:Learned cookie persistence mode

The following transactions occur in Figure 6-4:

•The website administrator configures the Px series application switch to use learned cookie persistence mode, and configures the name of the cookie to be tracked.

•The client at IP address 65.11.11.11 transmits its first TCP request (A) to www.buystuff.com at its publicly-known VIP address, 64.1.1.7.

•The Px series application switch responds (B) on behalf of 64.1.1.7, and the three-way TCP handshake is established between the client and the Px series application switch.

•Using its configured load balancing policy, the Px series application switch selects one of the web server. In this example, server 3 at IP address 10.1.1.3.

Px Series Application Switch Installation and Configuration Guide 6-11