Description of problem: Resolving using in-addr.arpa doesn't work at host: > host www.redhat.com www.redhat.com has address 209.132.177.50 > > host 209.132.177.50 50.177.132.209.in-addr.arpa domain name pointer www.redhat.com. > > host 50.177.132.209.in-addr.arpa > This also applies to ip6.arpa and ip6.int. Version-Release number of selected component (if applicable): bind-9.3.1-1_FC4 glibc-2.3.4-16 glibc-2.3.4-18 How reproducible: Everytime, see above. Even reproducible, if bind is rebuilt against -16 or -18. Older Rawhide glibcs, I didn't check. Actual results: Resolving using in-addr.arpa doesn't work at host. Expected results: > host 50.177.132.209.in-addr.arpa 50.177.132.209.in-addr.arpa domain name pointer www.redhat.com. > Additional info: I'm not sure, maybe this problem should be re-assigned to glibc.
The host command is perhaps not doing what you expect - the command: $ host 50.177.132.209.in-addr.arpa Will be looking up an "A" (address) record for 50.177.132.209.in-addr.arpa, and will also be using the search path in /etc/resolv.conf, so if your resolv.conf contains the line: 'search my.domain.com' host will be generating the queries 50.177.132.209.in-addr.arpa.my.domain.com. A ? 50.177.132.209.in-addr.arpa. A ? Giving host the IP address instead of the in-addr.arpa name makes it perform a PTR query for the in-addr.arpa name for the address, which is probably what you want: $ host 209.132.177.50 50.177.132.209.in-addr.arpa domain name pointer www.redhat.com. You could also use the -t option: $ host -t PTR 50.177.132.209.in-addr.arpa. 50.177.132.209.in-addr.arpa domain name pointer www.redhat.com. Or: $ dig 50.177.132.209.in-addr.arpa. Or: $ dig -x 209.132.177.50