When I put new entries into the NIST Net user interface, it seems to hang for a long period, then finally comes back. Whats going on?
Almost certainly this is due to a problem with domain name resolution on your system. In an attempt to normalize the appearance of names, when you enter a new name into the user interface, it does two DNS lookups: • A forward lookup of name to IP address, to find the address it will furnish to the kernel emulator. • A reverse lookup of that IP address to name, to find the “standard” form of the name it will then display. Usually, it’s the latter that gives problems. Try nslookup host and nslookup IP address for the entry you’re adding. If one of them fails, you can either fix your DNS server, or as a quick hack add the problem host/IP address to /etc/hosts on the NIST Net machine. This one seems to be a fairly common problem, especially affecting people who are not in a position to fix their DNS servers. So, in the latest versions, I have added a timeout around the DNS lookups. If they don’t succeed within a fairly short period of time, they are aborted. The code sets this time period
