[vox-tech] using a modem and ethernet concurrently

Ryan vox-tech@lists.lugod.org
Fri, 19 Dec 2003 23:37:40 -0800


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On Friday 19 December 2003 11:29 pm, Charles McLaughlin=20
cmclaughlin-at-ucdavis.edu |lugod| wrote:
> Hello,
>
> I'm having problems using my dial up modem and ethernet at the same time.
> This is a real bummer because I'm trying to set up a router/firewall, but=
 I
> think I need to work this out first!  ;-)
>
> I've found that I need to remove an iptable routing entry for the ethernet
> card in order to be able to use the modem.  And it is imperative that I
> remove that iptable entry before I dial up.

That's the routing table, not iptables

> Here is what I've done to get it to work:
>
> --------------
>
> The default:
>
> cmclaugh@linux-router:~$ route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 192.168.0.0     0.0.0.0         255.255.255.0   U     0      0        0
> eth0 0.0.0.0         192.168.0.1     0.0.0.0         UG    0      0=20=20=
=20=20=20=20=20
> 0 eth0
>
>
> I have to run the following **before** I dialup or else I won't be able to
> ping anything:
>
> cmclaugh@linux-router:~$ route del default gw 192.168.0.1
>
>
> Then I can dial up and connect:
>
> cmclaugh@linux-router:~$ pon                    # dials the modem, etc
>
> cmclaugh@linux-router:~$ route -n
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use
> Iface
> 169.237.17.97   0.0.0.0         255.255.255.255 UH    0      0        0
> ppp0 192.168.0.0     0.0.0.0         255.255.255.0   U     0      0=20=20=
=20=20=20=20=20
> 0 eth0 0.0.0.0         169.237.17.97   0.0.0.0         UG    0      0=20=
=20=20=20=20=20
>  0 ppp0
>
> -----------
>
> Does this seem normal?  To me, what I've done seems like a crude work-
> around.  Is there a better way to allow the modem and ethernet to live
> together in peace?

Why do you have a default route via 192.168.0.1? Do you have internet acces=
s=20
via a LAN?

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