Cookie persistence

Cookie persistence uses an HTTP cookie stored on a clients computer to allow the client to reconnect to the same pool member previously visited at a web site. There are 3 methods of cookie persistence available:

HTTP Cookie Insert method
HTTP Cookie Rewrite method
HTTP Cookie Passive method

HTTP Cookie Insert method

If you specify HTTP Cookie Insert method within the profile, the information about the server to which the client connects is inserted in the header of the HTTP response by BIG-IP. The cookie is named BIGipServer, and it includes the address and port of the server handling the connection. The expiration date for the cookie is set based on the timeout configured on the BIG-IP system. HTTP Cookie Insert is the default value for the Cookie Method setting.

HTTP Cookie Rewrite method

If you specify HTTP Cookie Rewrite method, Local Traffic Manager intercepts a Set-Cookie header, named BIGipCookie, sent from the server to the client, and overwrites the name and value of the cookie. The new cookie is named BIGipServer and it includes the address and port of the server handling the connection.
The HTTP Cookie Rewrite method requires you to set up the cookie created by the server. For the HTTP Cookie Rewrite method to succeed, there needs to be a blank cookie coming from the web server for Local Traffic Manager to rewrite. With Apache variants, the cookie can be added to every web page header by adding the following entry to the httpd.conf file:
Header add Set-Cookie BIGipCookie=0000000000000000000000000…
(The cookie must contain a total of 120 zeros.)

HTTP Cookie Passive method

If you specify the HTTP Cookie Passive method, Local Traffic Manager does not insert or search for blank Set-Cookie headers in the response from the server. This method does not try to set up the cookie. With this method, the server provides the cookie, formatted with the correct server information and timeout. It is recommend that you use the HTTP Cookie Rewrite method instead of the HTTP Cookie Passive method whenever possible.

Cookie profile settings

To implement cookie persistence, you can either use the default cookie profile, or create a custom profile. Table shows the settings and values that make up a Cookie profile.

Setting	Description	Default Value
Name	Specifies a unique name for the profile. This setting is required.	No default value
Persistence Type	Specifies the type of persistence. This setting is required.	Cookie
Cookie Method	Specifies the type of cookie processing that the BIG-IP system is to use. For more information, see HTTP Cookie Insert method, following.	HTTP Cookie Insert
Cookie Name	Specifies the name of the cookie that the BIG-IP system should look for or insert.	This value is autogenerated based on the pool name.
Expiration	Sets the expiration time of the cookie. Applies to the HTTP Cookie Insert and HTTP Cookie Rewrite methods only. When using the default (checked), the system uses the expiration time specified in the session cookie.	Enabled (Checked)
Hash Offset	With respect to Cookie persistence, this setting applies to the Cookie Hash method only.	0
Hash Length	With respect to Cookie persistence, this setting applies to the Cookie Hash method only.	0
Timeout	This setting applies to the Cookie Hash method only. The setting specifies the duration, in seconds, of a persistence entry.	180
Mirror Persistence	Specifies, when enabled (checked), that if the active unit goes into the standby mode, the system mirrors any persistence records to its peer. With respect to Cookie profiles, this setting applies to the Cookie Hash method only.	Disabled (Cleared)
Match Across Services	Specifies that all persistent connections from a client IP address that go to the same virtual IP address also go to the same node. With respect to Cookie profiles, this setting applies to the Cookie Hash method only.	Disabled (Cleared)
Match Across Virtual Servers	Specifies that all persistent connections from the same client IP address go to the same node. With respect to Cookie profiles, this setting applies to the Cookie Hash method only.	Disabled (Cleared)
Match Across Pools	Specifies that the BIG-IP system can use any pool that contains this persistence entry. With respect to Cookie profiles, this setting applies to the Cookie Hash method only.	Disabled (Cleared)
Override Connection Limit	Specifies, when checked (enabled), that the system allows you to specify that pool member connection limits are overridden for persisted clients. Per-virtual connection limits remain hard limits and are not overridden.	Disabled (Cleared)