[Techtalk] routing between networks...

[Julie]

Walt wrote:
> 
> Nils Philippsen wrote:
> Julie wrote:
> >Also, if she doesn't have a default route defined, or her gateway
> >to the outside world is other than the bridge between her two private
> >networks, she may well need a number of other routes.
> >
> >She doesn't, however, need "iptables" (which was another question).
> 
> My server on 10.0.0.1 provides internet
> access to my 10.0.0.0 network using IPTables.

It should be able to provide that to your 10.0.1.0
network as well, then.

> Can forwarding packets to/from the internet
> for the network on the other side of the bridge
> (10.0.1.0) be accomplished with routes instead
> of iptables?
> 
> Below is a rough diagram of my network...
> 
> _________       ___________     _________
> |10.0.0.1|      |10.0.0.2& |    |10.0.1.0|
> |gateway |______|10.0.1.1  |____|Network |
> |between |   |  | "Bridge" |    |________|
> |10.0.0.0|   |  |__________|
> |  and   |   |
> |internet|   |  __________
> |________|   |__|10.0.0.0 |
>                  |Network  |
>                  |_________|

"routes" and "iptables" are orthogonal.  You'll need to have a
route from the 10.0.1/24 net (what you call "10.0.1.0") over
to the 10.0.0/24 net so those packets can eventually make it
to 10.0.0.1.  So you need something like

route add -net 10.0.0.0/24 gw 10.0.1.1

on the machines on 10.0.1/24.  However, since "bridge" is
essentially the "gateway" for 10.0.1/24 to the entire internet
outside of the 10.0.1/24 net, you might as well just say

route add default 10.0.1.1

the "bridge" will route the packets which aren't for 10.0.0/24
to 10.0.0.1 because it should have a default route of 10.0.0.1.

The "gateway" machine (10.0.0.1) is what needs to run ip_tables,
and you said you're doing that already.
-- 
Julianne Frances Haugh             Life is either a daring adventure
txjulie at austin.rr.com                  or nothing at all.
					    -- Helen Keller