DNS leak with Squid???
I recently set up a pSense build. I have one ethernet port that runs a clearnet lan and a second ethernet port that runs everything through OpenVPN. I have checked, and everything that runs through the VPN has no DNS leaks.
Yesterday I installed Squid and SquidGuard using this guide (http://irj972.co.uk/articles/pfSense-proxy) with the idea of adblocking. The source is set to my VPN_LAN. For some reason now I have a DNS leak.
Does anyone know what could be causing the problem?
For some reason now I have a DNS leak.
Would you mind explaining what a DNS leak, in this context, means?
Do you mean that, because is now configured, clients supposed to use VPN assigned DNS are using another DNS?
Have you configured your VPN tunnel to force all traffic through the tunnel?
One aspect perhaps worth to highlight in case this is not already clear for you:
depending on your HTTP proxy configuration, name resolution is handled either by proxy or by client (browser side).
- with transparent proxy, as browser is not aware of any proxy in the middle, names (URLs) have to be resolved by client, meaning using DNS configured at client level.
- when relying on explicit proxy, client doesn't resolve any name but sends request directly to proxy in charge of the whole request, including name resolution.
Thanks for the reply.
By DNS leak I mean that DNS requests are now going through my ISP and not the DNS that my VPN uses. I realized this when running a speed test. Usually it selects a server close to the location of my VPN IP. After installing Squid it started selecting a server based on my physical location. I then went to a couple of sites that check for DNS leaks and they both said saying there was a leak. I did a test and uninstalled Squid and everything went back to normal.
In regards to your second post, I didn't realize that transparent proxy (which I did have selected) the clients resolved names. I figured that all DNS requests would be pased through the DNS that I have configured on the router (especially because I selected VPN_LAN as my input for proxy interface field in the server settings).
My firewall is set to force all traffic through the VPN. In fact, everything is set up to automatically cut if the VPN goes down. I also tried using the -Use Alternate DNS servers for proxy- field but that seems not to be working.
Is there anything else that is related to the proxy that could be somehow leaking my real IP address?
Either tell squid to use dns servers of your vpn provider, see squid doc for exact configuration parameters, or assign the vpn lan clients your vpn provider dns by dhcp. Or both.