GNOME Bugzilla – Bug 637894
NetworkManager VPN should (have an option to) replace DNS servers in /etc/resolv.conf
Last modified: 2016-03-11 17:42:32 UTC
If I configure a (PPTP) VPN in NetworkManger, the DNS servers I get via DHCP over that VPN connection are *prepended* to /etc/resolv.conf. This is good in that they get used first, but it's not quite enough. Here's the scenario: My two office DNS servers support DNSSEC validation. My ISP at home does not. When I connect to the VPN and try to resolve a name which fails DNSSEC validation (e.g. badsign-a.test.dnssec-tools.org), my office DNS servers return SERVFAIL (as per DNSSEC validation behavior). This causes libc to fail over to my ISP's DNS server. The result is that the domain name resolves, when it should fail. If this were a real attack instead of a test scenario, it'd have security implications. If I could make the VPN *replace* my DNS servers in /etc/resolv.conf, everything would work as expected.
not pptp-specific *** This bug has been marked as a duplicate of bug 656260 ***