Subject: Re: why doesn't NetBSD support bridge in kernel?
To: Markus A. Boeing <>
From: Will Waites <>
List: tech-net
Date: 07/05/2001 14:23:40
On Thu, Jul 05, 2001 at 09:46:28AM +0200, Markus A. Boeing wrote:
> Well, probably bridging is the most basic network function. Probably it is 
> the least desirable network function as well. If you're going to build 
> large networks that scale well and provide rich functionality, you're 
> better of using IP routing function instead of bridging technology.

Not  true.  Bridging  is  still  usefull in  some  circumstances.  For
example:  two providers  interconnect  and they  each  have their  own
802.1Q  vlan  tags that  they  use. Maybe  one  is  a transport  layer
provider doing  LAN extensions and the  other is an  ISP. Most likely,
since  there are  only 4095  useable  tags, there  will be  collisions
between the two tag domains. Solution: rewrite the tags. Unfortunately
none  of  the router  and  switch  vendors  (excluding some  high  end
catalyst switches  and juniper  routers -- very  costly, at  any rate)
support tag  rewriting. You can  do it on  a unix such as  NetBSD with
bridging support simply by bridging one vlan interface into another.

Blanket  statements  like  "routing   is  better  than  bridging"  are
nonsense. Granted people sometimes will  use one or the other where it
is not  appropriate and cause themselves headaches,   but that doesn't
mean that either is "better".