Nortel Networks WEB OS 212777 - Manual (Page 427)

Web OS 10.0 Application Guide
Chapter 16: Persistence n 427
212777-A, February 2002
Cookie Modes of Operation
Web OS supports the following modes of operation for cookie-based session persistence:
insert, passive, and rewrite mode. The following table shows the differences among the modes:
Each of the modes are explained in detail in the following sections.
Insert Cookie Mode
In the insert cookie mode, the Web switch generates the cookie value on behalf of the server.
Because no cookies are configured at the server, the need to install cookie server software on
each real server is eliminated.
In this mode, the client sends a request to visit the Web site. The Web switch performs load
balancing and selects a real server. The real server responds without a cookie. The Web switch
inserts a cookie and forwards the new request with the cookie to the client.
Figure 16-2 Insert Cookie Mode
Table 16-1 Comparison Among the Three Cookie Modes
Cookie Mode Configuration Required Cookie Location Uses Switch
Session Entry
Insert Cookie Switch only HTTP Header No
Passive Cookie Server and Switch HTTP Header or URL Yes
Rewrite Cookie Server and Switch HTTP Header No
Internet
1. Configure switch to insert cookie values
Web Server
Farm
Client
Web Switch Proxy Firewall
2. Client visits the Web site via HTTP request
3. Switch selects
server via SLB
4. Server responds
without any cookie 5. Web switch inserts a cookie and forwards the
request to the client.