This article provides solution to an issue where the session table on SRX gets exhausted and unable to create new sessions

SRX will be unable to create new sessions and the below messages will be seen in the flowtrace logs-

Aug 23 19:59:23 19:59:23.460815:CID-1:XXXXXX_ID-01-01:RT:Request session fail in lsys(0), reach maximum limitation
Aug 23 19:59:23 19:59:23.460815:CID-1:XXXXXX_ID-01-01:RT:Usage: 2096828/0, max: 2096828
Aug 23 19:59:23 19:59:23.460816:CID-1:XXXXXX_ID-01-01:RT:Error: sesion allocate
Aug 23 19:59:23 19:59:23.460817:CID-1:XXXXXX_ID-01-01:RT: packet dropped, no more sessions
Aug 23 19:59:23 19:59:23.460817:CID-1:XXXXXX_ID-01-01:RT:flow_initiate_first_path: first pak no session
Aug 23 19:59:23 19:59:23.460818:CID-1:XXXXXX_ID-01-01:RT: flow find session returns error.
Aug 23 19:59:23 19:59:23.460818:CID-1:XXXXXX_ID-01-01:RT:flow_proc_rc: -1.
Aug 23 19:59:23 19:59:23.460819:CID-1:XXXXXX_ID-01-01:RT: ----- flow_process_pkt rc 0x7 (fp rc -1)

There could be multiple reasons for session table exhaustion on SRX. To isolate the issue, session dump can be collected during the time of issue to find out the top talkers and filter unwanted traffic. One other possibility for such issues to occur is when 'inactivity-timeout never' option is configured for an application, leading to session table getting full.

2024-09-29 : Article Created