ppp(8) and dhclient(8)

[Andrew P.]

Hello!

I have a FreeBSD-4.10 host in my network. It's interface is 
DHCP-configured with a local ip-address, a dns server and a default 
route. The network is not connected to Internet, so the dns server 
resolves only local names and the default router only routes local 
packets. The host sometimes connects to internet via PPPoE. It receives 
new dns server and default route via IPCP.

The problem is that the new pair of dns/route seems to conflict with the 
old one.

DNS. I put enable dns and resolv writable in ppp.conf, ppp updates 
resolv.conf, but dhclient rewrites it in some seconds, leaving only 
local dns server in it.

ROUTER. Default route is configured at startup by dhclient. "add default 
HISADDR" in ppp.conf will result in error and will not change the route. 
So we can type "add! default HISADDR" or delete the route first with 
"delete default". But when ppp disconnects there's no more default route 
and local packets do not get routed.

I see possible workarounds somewhere around hacking dhclient-script, 
using multiple default routes with different metrics, or writing some 
own periodic scripts.

Is there an easy way to solve my problem?

Best wishes,
Andrew P.