Re: Overriding connections (VPN) that abuse DNS

[Ross Patterson <me rpatterson net>]

Derek Atkins <warlord MIT EDU> writes:

> Dan Williams <dcbw redhat com> writes:
>
>> On Sat, 2007-12-08 at 13:36 -0800, Ross Patterson wrote:
>>> This is somewhat related.  I have a poorly behaved VPN connection that
>>> sends NM empty DNS settings so that no DNS works when I'm connected to
>>> the VPN.  I can't fix the VPN, so my current workaround is to copy
>>> /etc/resolv.conf before I connect to the VPN, and then write it over the
>>> /etc/resolv.conf written by NM *after* connecting to the VPN.  IOW, I
>>> manually restore the original DNS configuration.  This is annoying to
>>> say the least.
>>> 
>>> My question is, is there a way to preseve the DNS settings on *just
>>> that* VPN connection so I don't have to do this dance every time?
>>
>> Not yet; but it can be fixed internally in NetworkManager pretty easily.
>> Nobody has come up with a patch yet, and I haven't had time.
>>
>> Internally, the IP4 configs are essentially a stack with between 0 and 2
>> configs per device.  The device's config is at #1, and the VPN config is
>> at #2.  Whenever the config stack changes, settings should get merged
>> with the higher numbered items taking priority over the lower numbered
>> ones.  Right now, a config with a higher number blows away the config
>> with the lower number entirely.
>
> I have a VPN that also gives me incomplete DNS info.  The way I fixed
> this was by writing a wrapper around /usr/bin/nm-vpnc-service-vpnc-helper
> that adjusts the vpnc environment before passing it back to NM via
> dbus.  In my case I needed to adjust the CISCO_DEF_DOMAIN variable.
> YMMV.

Well, I'm afraid I've perpetrated yet another case of user error.  I
swear I tried this before but checking both "Use Peer DNS" in the "PPP
Options" tab and "Peer DNS through tunnel" in the "Routing" tab seems to
fix the DNS problem I was having.  Who knows, maybe the ISP just finally
fixed their VPN.

Thanks for your time and sorry for the mistake.

Ross