We have several server based applications that open a TCP connection to remote servers for messaging back and forth. Some of the remote hosts we are connecting too are accessed via routers on the same lan segment and some are accessed via routers on a different lan segment off of the same Pro4060.
What we are experiencing is if we use the SonicWall as the default gateway to forward packets to the routers that provide access to the hosts, the SonicWall will reset the TCP connection exactly in 15 minute intervals. If we put static routes on our servers to forward packets directly to the routers ( by passing the sonicwall) than the connection remains constant. We can obviously put static routes on the serves where the routers are on the same segments but when the routers are on different LAN segments we have to go through our 4060
The TCP Connection timeout on the Pro4060 is set to 60 minutes. We have not really played with other settings. We are just wondering if there is some configuration setting we are missing or why SonicWall is RST'ing the connection. We have also experienced this with certain applications in the middle of a message flow.
Running wireshark on the servers we see the following packet after 15 minutes.
No. Time Source Destination Protocol Info
8 912.207429 172.16.13.140 220.127.116.11 TCP 48004 > 4286 [RST] Seq=1 Win=16560 Len=0
Frame 8 (62 bytes on wire, 62 bytes captured)
Ethernet II, Src: Sonicwal_02:cf:42 (00:06:b1:02:cf:42), Dst: Vmware_d9:f0:b2 (00:0c:29:d9:f0:b2)
Internet Protocol, Src: 172.16.13.140 (172.16.13.140), Dst: 18.104.22.168 (22.214.171.124)
Transmission Control Protocol, Src Port: 48004 (48004), Dst Port: 4286 (4286), Seq: 1, Len: 0
Source port: 48004 (48004)
Destination port: 4286 (4286)
[Stream index: 1]
Sequence number: 1 (relative sequence number)
Acknowledgement number: Broken TCP. The acknowledge field is nonzero while the ACK flag is not set
Header length: 20 bytes
Flags: 0x04 (RST)
Window size: 16560
Checksum: 0x3948 [validation disabled]
Does anyone know what this might be? I can provide the whole packet capture if needed.