Re: Bridging works great !

Madhusudana Rao (madhur@sasi.ernet.in)
Wed, 10 Jul 1996 19:39:11 +0500 (IST)


On Tue, 9 Jul 1996, Romano Giannetti wrote:

romano -> sorry for wasting your time, but could you point me to info on
romano -> configuring bridging, what it can do, etc?

If you have setup a router using Linux, it's simple. Otherwise,

What you need to do is :

1. Multiple ethernet cards.
Please check that each card has different IRQ and io port settings.
Please also check that each card works independently, ie, plug in one
card each and test them individually.

2. Getting the kernel to recognize the second interface card.
By default, the linux kernel probes only for the first interface card
So, you need to put a line similar to the one below in your lilo.conf

append = "ether=5,0x300,eth0 ether=11,0x320,eth1"

The above line is from my machine. The IRQ for the first card is 5,
the io port number is 0x300 and it's eth0. Similarly the IRQ for the
second card is 11, the io port is 0x320 and it's eth1.

3. /sbin/ifconfig eth1 ${IP2} broadcast ${BROADCAST} netmask ${NETMASK}
Please note that IP2, BROADCAST, NETMASK are the ones appropriate for
your host.

/sbin/route add -host IP2 eth1

4. Create two segments (Two LANs) and connect each of them to the Network
interfaces. Infact, you can have 4 such segments, by connecting 4
ethernet cards in your PC.

5. Download BRCFG.tgz via ftp from shadow.cabi.net:/pub/Linux directory.
Unpack this package, compile brcfg.c.

6. Just run "brcfg -ena" as root and then the action starts.

Try some other options like "brcfg -ena deb" to enable debugging, you
will get the packets flowing to and fro.

What I described above, is more or less what I did. For more information,
read the Multiple-Ethernet-mini-HOWTO, available via ftp (user: anonymous)
in sunsite.unc.edu:/pub/Linux/docs/HOWTO/mini.

According to Alan Cox, firewalling does not work. Can we actually hope
that firewalling work !!

/Madhu