Radware Alteon Application Manual page 590

Alteon Application Switch Operating System Application Guide
Persistence
Passive Cookie Mode
In passive cookie mode, when the client first makes a request, Alteon selects the server based on
the configured load-balancing metric. The real server embeds a cookie in its response to the client.
Alteon records the cookie value and matches it in subsequent requests from the same client.
Note: Radware recommends passive cookie mode for temporary cookies. However, you can use this
mode for permanent cookies if the server is embedding an IP address. In this case, a cookie has to
be eight characters long, and every two characters represent one byte of IP address encoded in
hexadecimal.
Figure 94 - Passive Cookie Mode, page 590
Figure 94: Passive Cookie Mode
Subsequent requests from Client 1 with the same cookie value are sent to the same real server (RIP
1 in this example).
When passive cookie persistence mode is enabled, Alteon creates persistent entries for server
returned responses with new cookie values within the same TCP connection.
Rewrite Cookie Mode
In rewrite cookie mode, Alteon generates the cookie value on behalf of the server, eliminating the
need for the server to generate cookies for each client. Instead, the server is configured to return a
special persistence cookie which Alteon is configured to recognize. Alteon then intercepts this
persistence cookie and rewrites the value to include server-specific information before sending it on
to the client. Subsequent requests from the same client with the same cookie value are sent to the
same real server.
Rewrite cookie mode requires at least 28 bytes in the cookie header. An additional eight bytes must
be reserved if you are using cookie-based persistence with Global Server Load Balancing (GSLB).
Note: Rewrite cookie mode only works for cookies defined in the HTTP header, not cookies defined
in the URL.
590
illustrates passive cookie mode operation:
Document ID: RDWR-ALOS-V2900_AG1302