after reinstalling one of our systems i started having the issue, incoming ftp-connections (and any other tcp/ip related connection) takes horrible long.
After looking around for a while on my system, i found this happens as soon as i provide a nameserver. Any incoming connection urges the server to do a reverse lookup, even for local adresses (192.168..).
I wonder if there is a way to tell the server to “never” do a reverse lookup or not to do a reverse lookup on local adresses (192.168.0.0/16 10.0.0.0/8 172.16.0.0/12). And i do not want to add all clients to the hostfile, nor do i want to miss a nameserver for connecting to the internet.