[H-GEN] Networking portables...

[Byron Ellacott]

On Sun, Oct 04, 1998 at 10:05:20PM +1000, Anthony Towns wrote:
> This means things like exim automatically knowing where the nearest relay
> is, and netscape/lynx just using the right proxy (without having to click
> here and click there all the time to tell it), having it just know its IP 
> address, getting remote printers to become "lp", and whatever else.
the same idea has occured to me in the past - the situation I have is
that eth0 and eth0:0 are configured to be on the 203.37.142.224/28 and
192.168.105.0/24 networks, respectively, and route -net entries added
for both.  However, at home, the default route is on the 203 range,
but at humbug it's on the 192 range.

The solution I sort of thought about but never got around to doing was
to allocate a different runlevel to each location (I only ever use
runlevel 2, and the single/reboot runlevels).  The runlevels can then
simply change routes and set different settings.

The trick is to get this to happen automatically.  For this, I could
think only of using ping(8) or a similar tool to see if a particular
host is available.  The implementation is left as an exercise for the
reader.

> The next problem is telling netscape and friends where their proxies are.
> There's not really too many options here, though -- you *have* to specify 
> the name of your proxy, and you *can't* (afaict) change it automatically.
> So you basically have to create a new name, and a TLD to go with it.
``and friends'' is taken care of via http_proxy.  for netscape itself,
use the automatic settings feature - a javascript file (that you can
of course change in the runlevel scripts) that tells netscape where
its proxies are.  simple.

> So on azure, I've got a DNS file that sets http-proxy.dynamic to point at
> azure, and on the server at work, http-proxy.dynamic points at the server
> itself. Then I can just set my proxies to http://http-proxy.dynamic:8080/ 
> and have it work.
or this way; or run a local proxy server, if you've got a beast of a
laptop :)  Or alternatively, transparently proxy at every available
place ;)

Disclaimer: I haven't tried any of the above.  I manually change the
routes, and for netscape I open preferences and change between manual
config and auto config.  manual is set for the home network, auto is
set for the uq network.  However, it should work. :)  The only trick
really is deciding which network you're on when you boot up.

-- 
Byron Ellacott
BInfTech: http://www.uq.edu.au
UQNGA: http://www.uqnga.org.au
Humbug: http://www.humbug.org.au