Re: Accessing a host with variable IP addresses / connection types

[Celejar <celejar@gmail.com>]

On Wed, 17 Apr 2019 08:37:20 +0200
Kevin DAGNEAUX <kevin.dagneaux@fiitelcom.fr> wrote:

> 
> > Hi,
> >
> > I've been bedeviled by this question for a while, but have been unable
> > to figure out a clean, non-hackish solution. It may be an XY problem ...
> >
> > I have a system (laptop, running Debian) that is sometimes connected
> > directly to my LAN, and sometimes connected via VPN (wireguard, to the
> > local router, running OpenWrt). The LAN is 192.168.0.0/24, with the
> > laptop having a fixed, static address in that range (although I'm
> > certainly open to using DHCP, possibly with a fixed address
> > reservation). The VPN is 10.0.0.0/24, with the laptop getting a fixed,
> > static address in that range (and wireguard apparently doesn't work
> > with dhcp).
> >
> > I currently have an entry in /etc/hosts on the various LAN hosts
> > assigning a hostname to the laptop's fixed local address, and the LAN
> > hosts can access the laptop via that hostname. [I could alternatively
> > use dnsmasq, which is running on the router regardless.] This obviously
> > doesn't work when the laptop is connected via VPN. [The laptop can
> > access the LAN hosts fine via their hostnames, so I seem to have the
> > routing correctly configured on the laptop and the router.]
> >
> > What I seem to want (but maybe XY?) is some way to adjust the host
> > files (or dnsmasq's information) so that the hostname will resolve to
> > the LAN address when the laptop is connected to the LAN, and the VPN
> > address when it's connected via VPN. If everything was using DHCP, this
> > would be straightforward enough, but as I said, the VPN apparently
> > needs to be configured statically, and not via DHCP. I could obviously
> > use some custom script (using, say, ageas, to modify host files) but
> > this seems hackish. What is a standard, 'correct' way to do this, or
> > more generally, to enable the LAN hosts to access the laptop
> > seamlessly regardless of its IP address and connection type?
> >
> > Celejar
> >
> Hi,
> 
> A possible solution is to use a bridged VPN, in this case, your laptop 
> will always have the same IP.

Thanks. I can't seem to find much information about this - can you
elaborate, or point me to a link? [I'm not a networking expert.]

Currently, my LAN is 192.168.0.0/24, which is also the addressing
scheme of some of the networks out of my control that I'm setting up a
VPN link from. I deliberately used 10.0.0.0/24 for the VPN to avoid
address collisions with these other networks. It did occur to me to
consider using a different address space, for the VPN or perhaps for the
whole home LAN, but I'd rather not take that step just to solve what
seems a relatively simple problem unless absolutely necessary

Celejar