SUMMARY: default route over a PPP link

From: Clara Hatem (
Date: Fri Aug 08 1997 - 11:43:00 CDT

Dear sun managers,

I asked the following:

> I have the following problem. it might look simple (and i think it IS),
> but it is giving me some headache , so please help if you can.
> Description:
> I am implementing a solution at a client site. The site consists of a
> TCP/IP LAN, with win 95 stations, and one netra i 150 server, with the
> following services running:
> entreprise web server
> smail (for the intranet mail, and internet mail over UUCP)
> anonymous ftp for the intranet
> DNS for resolving the local web
> Actual case:
> The site has a newly registered domain name,
> and a class C distributed over the LAN, x.y.z.0
> the ethernet card on the netra was assigned the IP x.y.z.1
> The others IPs are to be assigned to the win95 stations
> plus, the netra has a 28.8 modem connected to its serial port cua/a.
> This is used to connect to us (the isp), and exchange mail over UUCP.
> I just implemented this solution and it is working perfectly (cron job
> determines when to execute the uutry command to send mail, and recieve
> the mail of the domain we are also hosting the primary
> DNS to the domain.
> At the end, also note that when the netra server connects to us over
> dial-up, it is assigned a static IP a.b.c.180 (so interface ipdptp0 on
> the netra has the IP a.b.c.180). It connects to the PM having IP
> a.b.c.2.
> I am about to configure the netra and the win95 stations, in order for
> the LAN to browse the Internet over the PPP link of the netra.
> Configuration:
> I did the following:
> in the win95 client TCP/IP configuration:
> IP address : x.y.z.2
> gateway: x.y.z.1 (the netra ethernet)
> on the netra station:
> route add default a.b.c.2 1 (so the default route is our PM)
> and
> route add a.b.c.2 a.b.c.180 1 (so access it thru the serial port!)
> and that's it !
> it should work, no???
> I mean if I try to browse from a client station, the modem at the netra
> should dial us (the isp). but it isn't !!!!
> on the other hand, the route is Ok, since browsing from the netra causes
> the modem to dial (i.e. on demand)
> and also pinging the PM at our site (a.b.c.2) from the netra station
> causes the same.
> what am I missing ??? is it a DNS problem? I mean is the DNS server
> running on the netra trying to resolve the internet web sites, thus
> stopping the default route to be followed. (on the client stations i
> have specified the netra x.y.z.1 as DNS server, in order to be able to
> browse the intranet local webs. and I have specified the netra server to
> de a dns client to our dNS server, which is also the primary DNS of the
> domain
> or, is anything missing in the configuration I did (although I doubt it
> since I have already tested it at another site , which didn't have web
> or DNS running on the netra..)
> Thanks for your help.

> Regards,
> Clara Hatem

thanks for all your answers, which stated mostly that I should check if
ip_forwarding was enabled (set to the value 1) on the netra station, in
the following manner:
/usr/sbin/ndd /dev/ip ip_forwarding

and if not , to set it:
 /usr/sbin/ndd -set /dev/ip ip_forwarding 1

actually I checked and it was zero.
so I deleted the file /etc/notrouter, and rebooted the machine .
like expected , ip_forwarding became 1 automatically.
then I tried to browse from the client machine running win95, and it was
the problem is I was therefore running RIP on my machine, which I didn't
want, and which caused the PPP connection mot to time out like stated in (because RIP packets were always sent to the serial interface).
I don't want why actually, because I hav ein /etc/gateways : norip
so what i did is that I did a static route having the ethernet interface
as gateway, and the ipdptp0 (serial) interface as destination.
it worked, I rebooted the machine , which became working as a static
router , which means ip_forwarding became 2 and in.routed was killed,
and the timeout was respected (ppp session automatically disconnected at

Thanks for all of you,

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