[comp.protocols.tcp-ip] Bridge vs. router, or $ vs. $$$$$$

08071TCP@MSU.BITNET (Doug Nelson) (10/19/88)

>As I see it, routers offer one advantage over bridges.  They offer better
>firewall protection in case network problems occur.  Bridges, on the other
>hand,
>seem to offer two distinct advantages over routers.  First, they are protocol
>independent, i.e., they will pass decnet, tcpip, etc.  And second, they are
>much cheaper that routers.  ...
>
>Is my reasoning sound, or is there some major flaw that I am not aware of?
>Any comments would be welcomed.

I think I already responded in the first round, but I'll do it again.
We have the same setup here at Michigan State University, and I certainly
think your reasoning is sound.  We have a significant sized Decnet
community, and several other protocols which are in use between departments,
at varying points across campus.  A "flat" network makes a lot of sense here.

I have heard a lot of doomsaying about this type of configuration, but in
my experience I have not seen an undue number of network problems caused
by such a large ethernet community.  Our biggest problem is generally
the level of background/broadcast traffic on our net, of which a significant
portion comes from misconfigured hosts.  However, even these misconfigurations
are relatively benign; mistakes in configuration seldom affect other hosts.
Like your configuration, we only have one external gateway.  This makes life
very simple when it comes to routing issues.

Probably our biggest concern with this network is how soon we will run out
of capacity on a single 10Mb backbone.  But our solution there will be to
migrate our largest users to fiber.  When we do so, we'll have to begin
worrying about real routing, gateways, etc.

I don't see where you're in any serious trouble with your plans.

Doug Nelson
Michigan State University