A tunnel SSH SOCKS is a great way to quickly tunnel web traffic. But there is a problem. The DNS requests are still trying to connect locally instead to use the SSH tunnel.
Luckily, with SOCKS5 Firefox can control which side of the proxy handles DNS lookups. By default, it does the lookups locally resulting in the scenario above. To change this, set network.proxy.socks_remote_dns = true in about:config. This makes the SOCKS proxy more like a regular proxy, where DNS is handled by the remote machine end of the tunnel. Do the following for this:
In the browser location bar (the place where you type web addresses), type about:config and press [Enter]. This opens a different set of Firefox preferences. Where it says ‘Filter:’ at the top, type network.proxy.socks. The list of preferences will automatically change to show your proxy preferences. Highlight ‘network.proxy.socks_remote_dns’ by clicking it only once. Then, right-click it. This opens a small pull-down menu. Select ‘Toggle’ from the menu to change its value from ‘false’ to ‘true’.
Close Firefox and restart it.