Symptoms
Given a long-lived TCP connection that can carry multiple client requests (for example, but not limited to, HTTP requests), the BIG-IP system fails to forward requests after the forty-eighth one.
The client will try re-transmitting the answered request, but the BIG-IP system will persist in dropping it.
Impact
The BIG-IP system fails to forward traffic.
Conditions
This issue occurs when all of the following conditions are met:
1) The virtual server uses the FastL4 profile.
2) The virtual server also uses the HTTP or Hash-Persistence profiles.
3) The virtual server operates in DSR (Direct Server Return) mode (also known as N-Path).
Workaround
Do not use the HTTP or Hash-Persistence profiles with a FastL4 virtual server operating in DSR mode.
Note: It is fine to use an iRule that calls hash persistence commands (for example, "persist carp [...]") as long as the Hash-Persistence profile is not associated to the virtual server. This technique will allow you to persist on a hash based on L4 information that you can extract at CLIENT_ACCEPTED time. For example, the following iRule correctly persists a specific client socket to a pool member in a FastL4 DSR configuration:
when CLIENT_ACCEPTED {
persist carp [IP::client_addr]:[TCP::client_port]
}
