Internet presence problem
I have a very odd problem here. I have two Red Hat servers (7.2 and 7.3) with real Internet addresses. In the first one I have mainly apache with perl, ssh and qmail, and in the other I have bind and ssh. When I'm on the Intranet I can access those services without a problem, and If I'm working on the servers I can see internet. The problem is that after a while (about 15 mins or something like that), the servers can't be seen from the Internet, although they can be seen from the intranet where I'm working. The strangest part is that if I ping an Internet location from the servers when they are down to the Internet, they become available to be seen from the Internet again for a short while. Please help me, because I don't know what to do next.