Persistence

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Overview of Persistence Types

Reference: https://my.f5.com/manage/s/article/K26898044

Depending on session type, there are several persistence methods to choose from.

These are the supported persistence methods in F5 Networks BIG-IP units:

 

Cookie persistence
 

Cookie persistence uses the HTTP cookie header to persist connections across a session.  This technique prevents the issues associated with simple persistence because the session ID is unique.

 

Destination address affinity persistence
 

Also known as sticky persistence, destination address affinity persistence supports TCP and UDP protocols, and directs session requests to the same server based solely on the destination IP address of a packet.

 

Hash persistence
 

Hash persistence allows you to create a persistence hash based on an existing hash persistence profile. Using hash persistence is the same as using universal persistence, except that with hash persistence, the resulting persistence key is a hash of the data, rather than the data itself. A hash value may be created based on source IP, destination IP, and destination port. While not necessarily unique to every session, this technique results in a more even distribution of load across servers.
 

You cannot associate hash persistence with a virtual server that is managing Fast L4 traffic; use of hash persistence for Fast L4 traffic is disallowed.

Host persistence
 

Host persistence allows the BIG-IP system to use the HTTP Host header passed in an HTTP request to determine which pool member to choose. You can also activate host persistence from within an iRule.
 

Microsoft Remote Desktop Protocol persistence

Microsoft Remote Desktop Protocol (MSRDP) persistence tracks sessions between clients and servers running the Microsoft Remote Desktop Protocol (RDP) service.

SIP persistence

SIP persistence is an application-specific type of persistence used for servers that receive Session Initiation Protocol (SIP) messages sent through UDP, SCTP, or TCP. You generally use this persistence technique with stateful applications that depend on the client being connected to the same application instance throughout the life of the session.

Source address affinity persistence

Also known as simple persistence, source address affinity persistence supports TCP and UDP protocols, and directs session requests to the same server based solely on the source IP address of a packet.

SSL persistence

Because SSL sessions need to be established and are very much tied to a session between client and server, failing to persist SSL-secured sessions results in renegotiation of the session. BIG-IP system uses the SSL session ID to ensure that a session is properly routed to the application instance to which the session first connected. Even when the client's IP address changes, the BIG-IP system still recognizes the connection as being persistent based on the session ID.

Universal persistence

Universal persistence uses any piece of data (network, application protocol, payload) to persist a session. This technique requires the BIG-IP system to be able to inspect and ultimately extract any piece of data from a request or response.  With universal persistence, you can write an expression that defines the data that the BIG-IP system will persist on in a packet.

 

 

Cookie Persistence

Reference: https://my.f5.com/manage/s/article/K6917

When you configure a cookie persistence profile to use the HTTP Cookie Insert or HTTP Cookie Rewrite method, the BIG-IP system inserts a cookie into the HTTP response, which well-behaved clients include in subsequent HTTP requests for the host name until the cookie expires. The cookie, by default, is named BIGipServer<pool_name>. The cookie is set to expire based on the expiration setting configured in the persistence profile. The cookie value contains the encoded IP address and port of the destination server.

Reference: https://my.f5.com/manage/s/article/K83419154