dhclient with non present devices

[Sam Leffler]

incmc at gmx.de wrote:
>>Starting and stopping dhclient on removable interfaces is taken care of
>>by devd which calls the /etc/pccard_ether script.  You should have
>>ifconfig_ath="DHCP" and removable_interfaces="ath0" in your
>>/etc/rc.conf for this to happen.
> 
> 
> Hi,
> 
> thanks a lot, works great. However when deactivating my ath card sometimes
> freebsd doesn't renew dhclient for fxp0. So the system stays disconnected.
> Any   idea? As far as I understand it, dhlcient only gets restarted, when
> ath0 is comming up, not when it is going down. So the default routes stay
> on ath0, even if it's not present any more...

There is a single dhclient process.  It gets restarted whenever the set 
of interfaces that need dhcp changes.  In theory this should do the 
right thing.  In practice I've seen cases where the default route didn't 
move when an interface went away.  I suspect this is a problem in the 
dhclient script or maybe pccard_ether.

Regardless, the question of where to point the default route when there 
are multiple potential interfaces is not currently handled as well as it 
could.  You can hack the dhclient scripts to impose your own policy but 
I'd prefer to see something prepackaged.  Having kernel support for 
multiple default routes would also simplify things.

	Sam