Quoting Reco (recovery...@gmail.com): > On Fri, 28 Aug 2015 14:35:09 +0100 > Brian <a...@cityscape.co.uk> wrote: > > On Fri 28 Aug 2015 at 14:45:32 +0300, Reco wrote: > > > On Fri, 28 Aug 2015 12:09:08 +0100 > > > Brian <a...@cityscape.co.uk> wrote: > > > > On Fri 28 Aug 2015 at 10:01:59 +0000, Curt wrote: > > > > > On 2015-08-28, David Wright <deb...@lionunicorn.co.uk> wrote: > > > > > > > > > > > > $ host localhost > > > > > > Host localhost not found: 3(NXDOMAIN) > > > > > > $ ping localhost > > > > > > PING localhost (127.0.0.1) 56(84) bytes of data. > > > > > > 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.032 ms > > > > > > > > > > curty@einstein:~$ host localhost > > > > > localhost has address 127.0.0.1 > > > > > localhost has IPv6 address ::1 > > > > > > > > To complete the picture: > > > > > > > > brian@desktop:~$ dig -x 127.0.0.1 > > > > > > > > ; <<>> DiG 9.9.5-9-Debian <<>> -x 127.0.0.1 [...] > > > > ;; ANSWER SECTION: > > > > 1.0.0.127.in-addr.arpa. 10800 IN PTR localhost. [...] > > > > host and dig use only the DNS. > > > > > > > > Elimar's suggestion to use 'host $(hostname)' will work if hostname is > > > > a FQDN. But it shouldn't (or wouldn't) be on a stock Debian system. > > > > > > Not unless said 'stock Debian system' has 'search <domain>' stanza > > > in /etc/resolv.conf. > > > > Does "search example.org" count? :) > > It should count for the hosts in this domain. Provided, of course, that > one needs to resolve 'bare' hostnames (i.e. non-FQDN). > > > What is not understandable (to me) is why 'host localhost' resolves for > > some but not for others and why it is thought 'host $(hostname)' should > > resolve in the DNS. > > Stock Debian BIND configuration includes this wonderful snippet > (/etc/bind/db.local): > > ; > ; BIND data file for local loopback interface > ; > $TTL 604800 > @ IN SOA localhost. root.localhost. ( > 2 ; Serial > 604800 ; Refresh > 86400 ; Retry > 2419200 ; Expire > 604800 ) ; Negative Cache TTL > ; > @ IN NS localhost. > @ IN A 127.0.0.1 > @ IN AAAA ::1 > > Translating this to English - every BIND installed on Debian considers > itself the final authority on "localhost" zone and always returns > 127.0.0.1 for A queries (IPv4) and ::1 for AAAA queries (IPv6). > Other Linux distributions can store zone files elsewhere, but the > principle is the same. > Interpreting /etc/bind/db.127 (PTR entries) is left for an exercise for > the readers. > > So - 'host localhost' *should* work given an ideal world (because in > ideal world everyone will use an ideal DNS, which is BIND).
Why on earth would I want to use BIND on my LAN at home? Just so I have to read and understand RFC1035? No, I just put the hostnames and addresses into /etc/hosts. (And script it because I have five to do.) Debian correctly puts 127.0.0.1 localhost into /etc/hosts and hosts: files mdns4_minimal [NOTFOUND=return] dns into /etc/nsswitch.conf. So it's the hosts file that resolves localhost. DNS is not involved. BIND has to know the answer *in case* it's asked, not because it's *got to be* asked. My earlier posting (included above) was to show that, of the many suggestions made in this thread, "host" was not a good choice on a typical correctly-configured system. Cheers, David.
