[ale] Cable routing Explained

[marnuke]

>So, Charter Pipeline came by yesterday and set up their cable modem
service at my residence.  Still one-way, but that'll have to do for now.
And now on to the task of setting it up under Linux...

>I can do all the configuring, and I guess it will work, but can anyone
tell me how the routing works??

>The NIC attached to the cable modem is 10.0.0.1, and the dialup uplink
PPP address turns out to be 208.168.59.217, which is the same as the cable
modem's  address ( I think ).

>So, how does this work?  If I ping yahoo.com (ignoring the lookup
process), packets go OUT via ppp0 (default route), get to yahoo, and then
come back down. I assume Charter's end of the deal is smart enough to send
return packets via the cable (and not PPP).  But then what of Linux?  The
packets addressed to 207.168.59.217 end up appearing on the box's 10.0.0.1
interface!  How does the kernel know what's addressed to who?

>Also, would this pseudo route table work?
        default -> ppp0
        net 208.168.59.0 -> ppp0
        net 10.0.0.0 -> eth0

>(This is going to REALLY get confusing when I turn on both my analog
dialup, my cable dialup, my LAN NIC and my cable modem NIC all on the same
box..... woohoo!  So, help me understand this now :)

Eric




Ok good thing you have a Chater pipeline installer on the list
here's the scripts i use


/etc/ppp/ip.up.local

route add default ppp0
ifconfig eth0 up
ifconfig eth0 10.0.0.1 broadcast 10.0.0.15 netmask 255.255.255.240
route add -host 10.0.0.1 eth0
route add -net 10.0.0.0 netmask 255.255.255.0 eth0


then you would setup your ppp the normal way  nothing special
no pap is needed.

So where do you live??  I'm in stockbridge.