update Re: [Techtalk] interfacing ppp0 with eth0 ?

[Meredydd]

On Saturday 03 January 2004 00:35, mic wrote:
> summary:
> -gateway comp is on-line (thanks)
> -lan is functioning (right now as we speak i am sshing into the
> gateway from a lan comp)
> -this lan comp can not get access on-line otherwise
What do you mean by those last two? You are on a computer on your LAN, 
but not connected to the modem, and can't access the internet? What 
does the routing table on that computer look like, then?

> i couldn't think of why to give eth0 an ip address, so other than
> auto, i ignored it
Um, sorry, but which is eth0? Is that the ethernet card you're using for 
PPPoE?

> -su-2.05b# netstat -rn
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags MSS Window irtt
> Iface 66.123.200.254  0.0.0.0         255.255.255.255 UH      0 0    
>     0 ppp0 10.0.0.0        0.0.0.0         255.0.0.0       U       0
> 0         0 eth1 0.0.0.0         66.123.200.254  0.0.0.0         UG  
>    0 0         0 ppp0
> ----------------------------------------------------------------
> as i understand it,
> -line 1 says that anything destined for the outside world should go
> through ppp0
Ah, not quite. Line 1 says that anything going to 66.123.200.254 should 
go through ppp0.

> -line 2 says that anything destined for 10.x.x.x should go thru the
> eth1
Yep.

> and this is the line that i need to add some firewalling on.
Well, firewalling doesn't show up here, we'll get to that later

> -line 3 says that to go anywhere from the lan, use ppp0
Not quite. It says "to go anywhere (by which it means anywhere *else*, 
because if packets are going to 66.123.200.254 they've already been 
caught and routed, and if they're going to 10.x.x.x they've already 
been caught and routed), use 66.123.200.254 as a gateway, on interface 
ppp0."

> so i am not so sure why i am not getting on line from this lan comp,
> but i am sure there could still be many reasons.
Do you have NAT/IP Masquerading set up? If not, then there's no reason 
you *should* be routing packets through from your LAN to the outside 
world.

Meredydd