You must compile a kernel with IPforwarding or get someone
to compile a kernel for you.
>We have a PPP connection to our ISP, Linux 2.0.0 on both ends. On my side I
>have the Slackware96 distribution. My ISP has the Redhat 4.0 distribution.
>The modem on my side has IP address 194.19.7.242, the ISP has 194.19.7.241
>(gw6.oslo.no.powertech.net). We've been assigned a 32-network, network number
>
>194.19.122.160, with IP adresses ranging from 194.19.122.161 to
>194.19.122.190.
>I've set the default route using the following command:
>
> #route add default gw 194.19.7.241 metric 1
>
>pinging a machine outside of my own network works just fine from the Linux
>box, and any machine on my local network can easily ping that machine as
>well. It has IP number 194.19.122.161. However, when I try to ping an outside
>
>machine (on a different network), other than the modems address 194.19.7.242,
>
>I get a timeout. No response. I've set the default gateway to be that of the
>ethernet card (194.19.122.161) on the Linux machine on all the other machines
>
>in the network.
>
>We didn't get a broadcast address from our ISP, but I've tried to figure it
>out myself, and set 194.19.122.224 as broadcast. That might be wrong.
It is wrong. You also must configure your local ethernet devices with
the correct netmask here it is 255.255.255.(256-32) or 255.255.255.224
You said your 32 address range "network number" is 194.19.122.160
and uses addresses x.x.x.161 through x.x.x.190 for 30 "usable" addresses.
you lose 2 numbers of your 32 address group since one is the network address
and the other is the broadcast address.
Network address is 194.19.122.160
Broadcast is x.x.x.(network + size-of-group - 1) or x.x.x.(160 + 32 - 1)
##### giving Broadcast equals 194.19.122.191 ######
also recall netmask is 255.255.255.224
Of course you also need to have the kernel configured for IPforwarding :-)
Finally this should be a don't care but usually with ppp connections you
allow the pppd to setup the default route automatically.