# Lost TCP connection - how do I know what device is triggering the error message? **URL:** \ **Category:** Ignition\ **Created:** [January 31, 2023, 3:29pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213 "2023-01-31T15:29:38Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![compuzak](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@compuzak](https://forum.inductiveautomation.com/u/compuzak)\ **Post date:** [January 31, 2023, 3:29pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/1 "2023-01-31T15:29:38Z")
How do I know what device is triggering the following error message. It does not give an IP address or any way I can see that indicates what device it is. I tried looking for the [4840], but couldn't see any numbers associated with our devices. Here is the error message that displays every 2 minutes: INFO | jvm 1 | 2023/01/31 07:17:50 | E [d.T.TCPConnection[4840] ] [15:17:50]: Connection lost. INFO | jvm 1 | 2023/01/31 07:17:50 | java.io.IOException: End of stream reached. INFO | jvm 1 | 2023/01/31 07:17:50 | at com.inductiveautomation.iosession.socket.AsyncSocketIOSession.run(AsyncSocketIOSession.java:74) INFO | jvm 1 | 2023/01/31 07:17:50 | at java.lang.Thread.run(Unknown Source) ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [January 31, 2023, 3:42pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/2 "2023-01-31T15:42:31Z")
What version of Ignition is this? In current versions, there should be "device-name=something" metadata attached to the log entry. ---
**Author:** ![compuzak](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@compuzak](https://forum.inductiveautomation.com/u/compuzak)\ **Post date:** [January 31, 2023, 3:50pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/3 "2023-01-31T15:50:42Z")
we are still on 7.9.6. We are scheduled to update to the newest release in June ---
**Author:** ![pturmel](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/pturmel/32/3295_2.png) [@pturmel](https://forum.inductiveautomation.com/u/pturmel)\ **Post date:** [January 31, 2023, 4:01pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/4 "2023-01-31T16:01:23Z")
Then you'll need to monitor at the OS level, and look for TCP connections that are coming and going. Noting the remote IP addresses involved. Something like this in a Linux terminal on the gateway: ```auto watch -n 1 "netstat -tn4 |grep -v '127\.0\.0\.1'" ``` The `grep -v` excludes loopback connections. ---
**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\ **Post date:** [January 31, 2023, 5:30pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/5 "2023-01-31T17:30:57Z")
It's from the TCP driver: [UDP and TCP Driver - Ignition User Manual 8.1 - Ignition Documentation](https://docs.inductiveautomation.com/display/DOC81/UDP+and+TCP+Driver) Find whichever one is using port 4840. ---
**Author:** ![compuzak](https://avatars.discourse-cdn.com/v4/letter/c/71c47a/32.png) [@compuzak](https://forum.inductiveautomation.com/u/compuzak)\ **Post date:** [January 31, 2023, 7:11pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/6 "2023-01-31T19:11:07Z")
Ya, of course that is the port number, I should have realized that. Thank you for pointing that out, I of course found it out right away after that. Will be nice with the new release to give me a device name, that will even be easier. ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [January 31, 2023, 7:51pm UTC](https://forum.inductiveautomation.com/t/lost-tcp-connection-how-do-i-know-what-device-is-triggering-the-error-message/69213/7 "2023-01-31T19:51:33Z")
> [@compuzak](#): > > Will be nice with the new release to give me a device name, that will even be easier. When you look at the logs on the gateway webpage is there a little magnifying glass off to the right of these entries?