[Issue symptom] end client reported a large number of thin clients were in offline status on TCM Webportal.
TCM version: 5.6.000.000.83477
TC client model: CT3200
1.We checked the real-time situation, all TC were not able to register to TCM server.
2.We made the ping test from TCM to sereral TC, it's reachable.
3.we checked the port communication of port 8083/tcp from TC to TCM server, the telnet connection failed.
4.TCM and TC were in same subnet, and there was no physical firewall equipment, so we checked the local firewall working status and rules.
then we found the local firewall blocked the communication with TC.
5.we added the new rule to allow the port 8083/tcp to communicate with TCs by manual, finally, it's working.
The local firewall of TCM OS blocked the communication of TCs.
In local firewall poliy, adding the new rule to allow the port 8083/tcp to communicate with TCs by manual.