Re: dns.el: forget DNS servers in new network

[Leonidas Tsampros <ltsampros@upnet.gr>]

Lars Ingebrigtsen <larsi@gnus.org> writes:
> Ted Zlatanov <tzz@lifelogs.com> writes:
>
>> MHf> Thus the patch below.  It checks whether the names and IP addresses of
>> MH> all network interfaces have changed, and if so, rereads /etc/resolv.conf
>> MH> instead of using the value of dns-servers.  What do you think about it?
>>
>> I like it.  I wonder if it can be used more generally to find out if the
>> network has changed, a pretty common mobile case that can produce
>> connection timeouts.
>
> Yeah, it's a good idea.  Gnus should kill off all network connections
> when the IP address changes.
>
> It's not a 100% solution (you may be tethered behind a device that
> changes address, and they you won't discover the situation because your
> own IP address doesn't change), but it's better than nothing.
>
> However, I wonder whether this could be done more generally?  That is,
> allow functions to "register" actions to be done when the IP address
> changes, so that we don't have to duplicate this code in several
> packages...

I really like this too!

Having a device change a network, for example from work to home or more
imporantly from work to a public hotspot (e.g. airport, starbucks,
cofeehouses, libraries etc), can lead to "information leaking".

For example, I do not want my Gnus to try connect to my job's mail server
when at the home network.

I was thinking that a regural DNS /etc/resolv.conf polling of the
"search" parameter would be nice. So if we see "search corporation.com"
you know I'm at WORK (so kill connection X and don't try and reconnect
to server Y) but if it is set to "search home.lan" hey i'm at home now
kill connections BLABLA and don't try to connect on server KOKO.

I know that I'm talking about a different problem here, but IP changes
usually comes from changing networks and I want my mail reader to be
"location aware" since ip readdressing is not an everyday task.

I hope I'm making sense :).