[plug] Route (again)

[Matt Kemner]

On Tue, 16 Jul 2002, quoth Jonathon Bates:

> After tracing to an IP within the LAN, it stops at the router and then
> goes back and forth between the previous hops.

So you're saying your Linux Router is routing it back to your ISP?

That suggests your Linux box doesn't have a route to your LAN

> >      "cat /proc/sys/net/ipv4/ip_forward" should give you a "1"
>
> If I may ask, what exactly does this do? I thought it was only used
> for masq'd hosts (I have tried doing this to no avail).

It enables IP forwarding. IP forwarding is where it allows packets to come
in one interface and go out the other - essential for a router.
Masq'ing is just a special kind of router.

> > 5. If all else fails, tcpdump is your friend.

> I have tried this and from memory if i am trying to get in, no activity
> occurs on the 203.1.2.3 subnet

Again suggesting the Linux Box does not have a route to your 203 subnet.

> > What is the output of  "route -n" ?
>
> >From memory they were the basic routes.

Can you paste me a copy of the output? Send it privately if you prefer.
Output from an external traceroute would be useful too

 - Matt