Linux as a bridge ?

Madhusudana Rao (madhur@sasi.ernet.in)
Sat, 13 Apr 1996 18:33:54 +0500 (IST)

What is the new bridge code in the Linux kernel ? The Configure.help
says that one can configure a Linux box to act like a bridge. What
administrative tools do I need to use my Linux as a bridge ? What else
can I do with this bridge apart from simply having connectivity between
two segments? Is it possible to selectively block certain IPs on one
segment ? Is this bridge self learning or do I need to configure it ?

Having bridging ability in the kernel is really great.

I thought I would test out this new bridge code, so :

I picked up the v1.3.87.

With bridging code enabled in the kernel, my system does not boot at all.
It hangs after recognizing the second interface card, at the point :

-----------------------------------------
ne.c:v1.10 9/23/94 Donald Becker (becker@cesdis.gsfc.nasa.gov)
NE*000 ethercard probe at 0x300: 00 80 c8 1e 1a 1a
eth0: NE2000 found at 0x300, using IRQ 5.
NE*000 ethercard probe at 0x320: 00 80 c8 1e 1a 45
eth1: NE2000 found at 0x320, using IRQ 11.
-----------------------------------------

I am sure, I have set up the two cards and configured them alright. If I
disable bridge code, everything works and I could reach my Linux system
from both the segments.

My system works perfectly okay with most of the 1.3.x kernels and with
1.3.87 (without bridge).

Any clues ... Am I missing anything ? Where can I get some documentation
on this bridging code and it's future releases ?

/Madhu