I don’t know who is supposed to keep the Pkgfile updated, but the dhcp package is still pointing to 3.0.5. The ftp directory for this version has moved

The source was

http://ftp.isc.org/isc/dhcp/dhcp-$version.tar.gz

and now should be

http://ftp.isc.org/isc/dhcp/dhcp-3.0-history/dhcp-$version.tar.gz

Tal