I'm running MySQL5.6.3 on a CentOS 6.1 virtual machine running on Windows XP in VirtualBox.

The network card is configured in bridge mode, so my physical & virtual machines share the same ethernet card.

On the virtual machine, everything works fine: internet access, DNS lookups. However, connections to the MySQL daemon take a while, and the logs keep showing this warning:

[Warning] IP address '' could not be resolved: Temporary failure in name resolution is my host machine on which I'm runnning the MySQL client.

Looks like although DNS lookups work fine, reverse DNS lookups end up in a timeout.

Here is the virtual machine configuration:

# cat /etc/sysconfig/network-scripts/ifcfg-eth0

# cat /etc/resolv.conf

Is there something wrong in my network configuration?


1 Answer 1


IMHO This sounds like you need mysqld to stop using DNS.

Please do the following: Add this to /etc/my.cnf


Them restart mysql. From then on, mysql will no longer resolve addresses via DNS.

Give it a Try !!!


Please read these options in the MySQL Documentation:

Also, there is one restriction to using this: You cannot use DNS names in the host column of any of the grant tables.

UPDATE 2012-12-17 08:37 EDT

I was recently asked if skip-host-cache and skip-name-resolve could be set without a mysql restart. Let's find out:

mysql> show variables like '%host%';
| Variable_name | Value        |
| hostname      | ************ |
| report_host   |              |
2 rows in set (0.00 sec)

mysql> show variables like 'skip_%';
| Variable_name         | Value |
| skip_external_locking | ON    |
| skip_name_resolve     | OFF   |
| skip_networking       | OFF   |
| skip_show_database    | OFF   |
4 rows in set (0.00 sec)

mysql> set global skip_name_resolve = 1;
ERROR 1238 (HY000): Variable 'skip_name_resolve' is a read only variable

As shown, skip-host-cache is not visible in the list of global variables. As for skip_name_resolve, it was visible. However, it cannot changed dynamically because it is a read-only variable.

Therefore, skip-host-cache and skip-name-resolve can only be changed via a mysql restart.

  • Do we have any problems as effect of disabling DNS look ups ?
    – Uday
    Jun 19, 2012 at 17:49
  • @Uday the only concern within mysql is this: You cannot use a DNS name effectively in the host column of mysql.user. If you have any, you need to replace them with the public or private (preferable) IP address instead. Jun 19, 2012 at 18:01
  • @RolandoMySQLDBA is there a way to add skip-host-cache and skip-name-resolve without restarting MySql?
    – Ran
    Dec 17, 2012 at 4:45
  • @Ran Sorry, the answer is no. I updated my answer to reflect this. Dec 17, 2012 at 13:37
  • Can there be any possible problem like connectivity from localhost or any other issue? I'm facing problem for ip
    – Malay M
    May 22, 2017 at 10:22

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