We have an Lenovo server working well since one and a half year. Sudenly, we started having issues to connect to it from our office network. I reinstalled ubuntu 16.04 sever on it. It has two ethernet ports, one used for the public ip and another for the internal network.
When trying to connect with a mobile network or one specific server from our local office network, all works well, but as soon as I am trying to connect to it from my or my colleagues local PCs, or another office server, I am getting a timeout, both on ssh port, 80, 443 etc.
The server side has a firewall, but that's not the issue as from the same network, the connection works from some machines, but not from others?
Thank you.