dhclient-script, hooks, and changing the environment

[Theodore Tso]

On Wed, Aug 06, 2008 at 09:10:56PM -0300, martin f krafft wrote:
> Anything else? Do you know of packages that rely on this
> functionality? Do you have scripts of your own which modify the
> environment? Would you please be so kind as to explain to me what
> they do, and help me figure out whether there isn't a better way for
> them?

In the past I've used dhclient-enter-hooks.d to work around buggy
hotel networks which advertise a gateway for the default route which
is outside the local network.  So I used a dhclient-enter-hooks.d
script to hack the netmask returned by the DHCP server so that the
default route would be accepted.  (Unfortunately, Windows allows the
default route to be outside the local network arrange of the ethernet
interface, and apparently if there is only one ethernet interface,
Windows will assume that instead of rejecting the route, or dropping
packets on the floor, to do the convenient-but-wrong thing of assuming
the packets should go out via the default route to the ethernet
interface, even though the default route is an invalid non-local
address for that interface.  As a result, trashy hotel networks have
no incentive to fix their DHCP servers, since they work just fine on
Windows laptops....

						- Ted