Re: Transparent network bridge+filter?

[Jeff Noxon <jeff@planetfall.com>]

You have an interesting idea, but it won't work in my case.  I have to
put this between a pair of Cisco routers running EIGRP.  They won't see
each other if the router discovery packets (etc.) aren't forwarded by
a bridge.  I also can't guarantee that the address of the router on one
side won't change -- it is not under my control.

Thanks!!

Jeff

On Wed, Jan 19, 2000 at 08:42:00AM +0100, Onno Ebbinge wrote:
> At 02:08 PM 1/18/00 -0600, Jeff Noxon wrote:
> >Can anything that runs on Linux do reliable network bridging & filtering?
> >I need a transparent filter that I can drop into an existing network.
> >
> >Ipfilter will do the job with Open/NetBSD.  It may work on Linux, but
> >requires kernel 2.0.35 and isn't compatible with glibc.
> 
> Another guy ask -something like that- before,
> I replied with an answer that worked ;-)
> 
> Here is my reply and maybe you can use 
> parts of it:
> (You don't want to use this route config ;-)
> 
> > This has been a while but here it goes:
> > 
> > Please test if the next settings will do the trick.
> > The debian box cannot be reached from the inet or lan,
> > We can do something about the lan connection though...
> > 
> > Note: Filtering firewall is WIDE open!
> > Note: There is a route for all IP's because they are 
> >       on the same subnet (netmask) but NOT on the 
> >       same network device!
> > Note: Youre gateway is 63.225.131.78
> > 
> > root# ifconfig lo 127.0.0.1
> > root# ifconfig eth0 0.0.0.0 promisc
> > root# ifconfig eth1 0.0.0.0 promisc
> > 
> > root# route add 63.225.131.73 eth0
> > root# route add 63.225.131.74 eth0
> > root# route add 63.225.131.75 eth0
> > root# route add 63.225.131.76 eth0
> > root# route add 63.225.131.77 eth0
> > root# route add 63.225.131.78 eth1
> > 
> > root# ipchains -P input ACCEPT
> > root# ipchains -P forward ACCEPT
> > root# ipchains -P ouput ACCEPT
> > root# ipchains -F
> > root# ipchains -X
> > 
> > Please send me your results....