Dear All,

There is a Debian firewall, which works fine, but there is one strange problem: There are some locations on the internet, from where it is not possible to access the server (VPN, web, ping, etc. doesn't work). It works almost from everywhere, just a couple of locations experience this problem. Do you have any idea? Have you experienced anything like this? Traceroute says that the packets are lost at the server.

Thank you for your suggestions.