Nmap Packaging Bug
I’ve recently upgraded to nmap 5.21 on my Fedora 12 box, and it turns out that the RPM’s distributed by Fyodor can’t resolve hostnames (even localhost, uname or /etc/hosts entries) apparently due to his build environment being CentOS 5.3 which has a difference glibc and gethostbyname() implementation. A “fix” is to start the nscd service.
The problem seems to exist in at least 5.00, 5.20 and 5.21 RPM’s of nmap, however ncat works fine.