Hi.
On Sun, Oct 28, 2018 at 04:17:17PM +0300, Reco wrote:
> Hi.
>
> On Sun, Oct 28, 2018 at 02:13:30PM +0100, Pierre Frenkiel wrote:
> > On Sun, 28 Oct 2018, Reco wrote:
> >
> > > strace getent hosts bad.solutions
> >
> > thanks for your answer, but the output is rather obscure for a non-guru
> > user,
> > except a lot of "no such file or directory"
> > In particular, I don't see how to explain the difference of behaviour on
> > my 2 computers.
>
> Not pretending to be a guru, but can you post the results somewhere?
I don't repost those two strace outputs, archives will be better without
them.
The result is somewhat unexpected (to me at least):
Judging from multiple:
stat("/etc/resolv.conf", 0x7ffbffffae40) = -1 ENOENT
The host's resolver is configured for conventional DNS resolution.
/etc/resolv.conf is not present, so resolver tries to find DNS at
127.0.0.1 udp:53:
connect(3, {sa_family=AF_INET, sin_port=htons(53),
sin_addr=inet_addr("127.0.0.1")}, 16) = 0
Which it does (zero return code), and sends DNS query there:
sendto(3, "\307N\1\0\0\1\0\0\0\0\0\0\3bad\tsolutions\0\0\34\0\1", 31,
MSG_NOSIGNAL, NULL, 0) = 31
And something that's listening udp:53 on your laptop replies:
recvfrom(3, "\307N\201\200\0\1\0\0\0\1\0\0\3bad\tsolutions\0\0\34\0\1\300"...,
1024, 0, {sa_family=AF_INET, sin_port=htons(53),
sin_addr=inet_addr("127.0.0.1")}, [28->16]) = 91
The fact that libc's resolver have a hardcoded fallback to localhost in
the absense of resolv.conf was not known to me until now, but it's
documented at resolv.conf(5):
If this file does not exist, only the name server on the local
machine will be queried
So, answering your original question, you have working name resolution
because you have a caching nameserver on your laptop. My money's on
dnsmasq.
Reco
