I have several Ubuntu servers. Two of them are working as DNS servers. One of my name servers (let's call it DNS1) went down for maintenance. I sill had another DNS server running (DNS2).
All other servers are configured to use the nameservers as follows
/etc/resolv.conf
:
nameserver DNS1
nameserver DNS2
I can still resolve DNS names using the DNS2 server, but the name resolution takes a long time. It is clear to me that any given server is first trying to access DNS1, and then it is trying DNS2 after failure.
I tried to swap the two lines. The name resolution became too fast.
I am wondering if there is a way to dynamically change the resolv.conf
file based on the state of the configured nameservers. Of course, I can write a shell script myself to do the job. But I prefer to find a better way if there is one.
No a direct solution but you can smooth things a little by adding options to your
resolv.conf
for instance :the default for
timeout
is 5 seconds, and default value forattempts
is 2.