This addon for Node.js allows you to get the system's DNS configuration under Windows.
It doesn't work on *nix, where you can simply read /etc/resolv.conf to get the system's DNS servers.
This project is available on npm. Since it is a native (C++) addon, you'll need everything node-gyp needs to build projects, which includes Python 2.7 and MS VC++.
> npm install winnetinfo
Alternatively, you can download a compiled binary here if you're in a hurry (and taking candy from strangers is your thing).
var ni = require('winnetinfo');ni.getNetworkParams();
You'll get something like this:
{ hostName: 'daguej',
domainName: '',
dnsServers:
[ '8.8.8.8',
'8.8.4.4', ],
dnsEnabled: false,
nodeType: 4,
domain: '',
arpProxyEnabled: false,
routingEnabled: false,
dhcpScope: '' }