[H-GEN] Networking portables...

[Bruce Campbell]

On Mon, 5 Oct 1998, Byron Ellacott wrote:

> 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 original hydra's networking script was amusing.  It was a machine that
could be in one of 4 locations, with known (different) IP addresses and
gateways in each.

So when it booted up, it would do the equivilant of:

	"Hello, am I in the Maths department?"
	"No, am I on the lecture subnet?"
	"No, then am I at Michael's place?"
	"No, then I must be at Bruce's place."

By the simple joy of ifconfig eth0 up this_address ; ping this_router ;
check result ; repeat until happy.

> > 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.

Not really.  Although not implemented in the above, it would be simple to
set up (based on where it works out it is) say the TIS firewall toolkit's
plug-gw, or IPFW masquarading to redirect known ports on localhost (which
lynx, netscape etc point to for their proxy, exim and the like point to
for a mail forwarder) to external machines and ports.

Heck, if you were really into it, you could encourage the use of WKS
fields by everyone (Well Known Service) to dynamically pick up where proxy
requests should be sent to, mail hosts etc etc, no matter where you were
(should point out that DHCP does let you do some of this)

> > 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.

Setting up a fake TLD is a perfectably workable solution... if you control
the DNS servers in all locations where the machine would be plugged in
(assume that you are redirecting local ports for the proxies etc)

--==--
Bruce.