If I cat my resolv.conf, I see this message:
#
# Mac OS X Notice
#
# This file is not used by the host name and address resolution
# or the DNS query routing mechanisms used by most processes on
# this Mac OS X system.
#
# This file is automatically generated.
#
I am trying to add a DNS entry. I edited my hosts file and flushed the dns cache, but the name is not resolving if I use host servername
. I thought perhaps that host
was not configured to look at the hosts
file. How can I get my new entry to resolve, and what is OSX using if not resolv.conf
?
Answer
The host tool does not simply resolve names (as in, using the system name resolver) but actually queries dns servers (as in, sending packets to udp/53 and possibly tcp/53): it doesn't know nor use the local hosts
file.
If you want to test the operating system's resolver (as in, gethostbyname() and similar libc functions) you can try to ping the name you added to /etc/hosts
and it will honor what you put in that file.
Also, as you already found out DNS lookup on Mac OSX does not use /etc/resolv.conf
, and the correct way to configure which DNS servers are queried is in the Network Settings gui and/or networksetup
commandline tool. I honestly don't know if you can configure the order in which sources are tried, but the standard behavior is to try /etc/hosts
first and dns servers after that.
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