Linuxconf send the following query to the DNS
nslookup -q=soa 0.0.127.in-addr.arpa
It is believed that all properly configured DNS should answer this request. It is possible that a working DNS operates without a reverse mapping for the network 127.0.0. This is a flaw and should be corrected. (Run linuxconf on this machine and configure the DNS with it and linuxconf will silently fix this)