Slow initial connection delay for redhat server

[happydude]

Yup, I've tried disabling the FTP service completly, telnet and web pages still load with the initial delay.

Is there away of disabling reversedns lookup completly for the entire computer? Not just for each application seperatly?

I'd like to test it with no reverse dns lookup, see if it loads normally again.

[andutt]

I dont know how to disable it completly, but you can go around DNS lookups by setting the hostnames and ipadresses in /etc/hosts. Then when someone want to resolve and adress it will find it localy and doesnt have to resolve it with an external DNS.

Make sure though that:

#hosts:     db files nisplus nis dns
hosts:      files dns

This is how your dns-entrie should look like in /etc/nsswitch.conf that means that questions will be resolved in local files before dns. You can also put a # before your entries in /etc/resolv.conf to enforce local questions only.

[Dolda2000]

I didn't mean for you to disable the FTP service. Just make a connection to it, find the PID of the FTP server and attach gdb to it and generate a backtrace. That will tell you if it actually is the reverse DNS lookup that's taking time or if it is something else. I'm suspecting that it might be something else, since my IP address resolved instantly with "host".