At work we use OpenDNS and it has wrongly blocked irc.freenode.net for malware. How can I make sure that any request for *.freenode.net goes to and (Google's DNS).

I tried doing this by fiddling with resolv.conf on Ubuntu, but I wasn't able to get too far. Also, is there an easy way to do this for Mac and Windows systems (I have a few colleagues using those OSes and they'd like to use IRC as well).

  • 5
    Be careful - attempting to get around security controls can get one escorted out of some companies. Also, it is possible other DNS servers are blocked.
    – uSlackr
    May 23, 2012 at 17:09

8 Answers 8


Linux does not support the use of domain-specific DNS servers via resolv.conf. You could potentially work around this by running a caching nameserver (such as BIND or dnsmasq) locally and then configuring explicit forwarders for each domain.

Under OS X, this sort of setting is relatively easy using the scutil command. The common use case for this configuration is to forward DNS requests for a VPN connection to VPN-specific DNS servers, so you'll find this discussed often in concert with, e.g., OpenVPN. This document talks about the scutil command as does this, and a Google search for openvpn and scutil will yield more results.

I'm not sure about Windows. You could presumably use the local DNS server solution for all three platforms if you needed to.

  • 1
    Is this still true in the systemd-resolved world? (Yes I realize your answer is 7 years old)
    – Pointy
    May 1, 2019 at 20:21
  • 5
    @Pointy It seems recent versions of systemd-resolved can handle this: gist.github.com/brasey/…
    – corford
    Dec 6, 2019 at 20:46
  • 1
    Windows can do it using NRPT rules: Add-DnsClientNrptRule -Namespace "example.com" -NameServers "" Jan 25, 2020 at 18:07

This can't be done with the standard DNS resolution provided by *nix (and Windows AFAIK), you need your own DNS server to do this. On *nix dnsmasq is the best choice for this, and you can either run this on every workstation or run it on a server and configure all the workstations to use this.




  • 3
    This can absolutely be done using the standard DNS resolution provided by some operating systems. Just not by Linux.
    – larsks
    May 23, 2012 at 17:00
  • To control which interface to use I added the @vpn0 at the end of the DNS servers. This can be useful to use it only when a VPN is up.
    – Zioalex
    Apr 26, 2019 at 13:27

Under OS X you can use files like /etc/resolver/example.com with content:


to forward dns requests for *.example.com to


  • Does this apply for High Sierra ?
    – Tolsadus
    Oct 10, 2017 at 16:46
  • 2
    It still works on Mojave
    – byte255
    Feb 16, 2019 at 9:15

You can do it on Windows with PowerShell:

Add-DnsClientNrptRule -Namespace "pqr.com" -NameServers ""

Reference: https://docs.microsoft.com/en-us/powershell/module/dnsclient/add-dnsclientnrptrule?view=win10-ps

  • It's a pity that no support for wilcard namespace.
    – John Lee
    Jun 9, 2022 at 8:45

It's possible to use firejail --dns option for this. For example:

firejail --dns= firefox

This way dns server can be set per application instead of per domain. So it might be a better solution in some circumstances.


I did this on Fedora by installing a local DNS server.

first install bind:

sudo dnf install bind

step 1: append a line to /etc/named.conf (as root):

include "/etc/named/freenode.net.conf";

step 2: create the zone file /etc/named/freenode.net.conf (as root):

zone "freenode.net" {
    type forward;
    forwarders {; };

now restart named:

sudo service named restart

now reconfigure your lan settings to use as the DNS server, rather than the DCHP-allocated hosts.


If you are using Windows DNS Manager for most of your domain when accessed locally, but want to delegate one host (or for a few, if you repeat the steps below) to an external DNS provider, then you can do the following:

  • First delete any previous local A or CNAME record for the hostname you are going to delegate
    • These are found in the main window for 'DNS Manager/dc-name/Forward Lookup Zones'
  • Then right-click on your forward lookup zone, e.g. 'DNS Manager/dc-name/Forward Lookup Zones/foo.com', and select 'New Delegation...'
  • Fill in the delegated domain for the single host you want to delegate, e.g. mail.foo.com
  • In the next step, populate one on more nameserver names, each with one or more IP addresses (IP addresses are required here, and I assume this means they are not dynamically looked up in future, unfortunately)
    • You can look up these values, e.g. on an external Linux machine, using: whois foo.com (note, not mail.foo.com) to find the nameserver(s) (you should look or grep for lines starting with Name Server); then host ns1.mydnscompany.com (for example) to find the ip address(es) of the name server(s)
  • Finish the wizard, everything should now be set up
    • As normal, you may need to run ipconfig /flushdns on a client if you want to see the changes immediately
    • If the delegation does not show up in DNS Manager (immediately below the forward lookup zone in the navigation tree), even after right-click 'Refresh' to refresh the DNS Manager view, try re-checking the first step

We are encountering similar requirements when connecting with OpenVPN, and OpenVPN provides a solution known as split-DNS (https://openvpn.net/vpn-server-resources/troubleshooting-dns-resolution-problems/). This feature allows the resolution of specific domains over the VPN DNS server, while other domains are resolved via the local DNS server.

To enable split-DNS, the following directives should be included in either your OpenVPN server or client configuration:

dhcp-option DNS
dhcp-option DNS
dhcp-option DOMAIN freenode.net

I have tested these options on macOS, and they work well. However, on Linux, you need to use the script available at https://github.com/jonathanio/update-systemd-resolved

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