Routing With Netatalk

An easy and cheap way to segment an ether-network of macs .

When you get more than 20 machines on the one physical network, things start to slow down. This is because, with ethernet, only one computer can talk at a time. Even if you've got three hubs "daisy chained", it is still one network.

AppleTalk is self configuring for the client. This is a Good Thing, and is in stark contrast to TCP/IP. But this self configuration comes at a cost - AppleTalk is a very "chatty" protocol, and uses a lot of network bandwith whereas TCP/IP is nice and quiet.

In our case we had three rooms with five hubs and 45 computers. The hubs were daisy-chained in a messy sort of way. Not good. Collisions were around the 70% mark!

Two solutions to this.

• Buy a switching hub - about US$800 or so. A good solution if someone else is paying for it.
• Buy a few extra ethernet cards for your FreeBSD box - about US$25 each or so. A good solution if you are paying for it. Join each hub to FreeBSD, (no more daisy chaining). Use netatalk on FreeBSD as a router between the rooms.

Several people have asked for a working sample of an atalkd.conf file that seeds zone names and routes between those zones, so here it is:

In this setup, I have three ethernet cards. FreeBSD calls these cards "ed0" "ed1" and "ed2". Each of the three computer room has an ethernet hub, with ed0 going to CR1, ed1 to CR2 and ed2 to CR3

The atalkd.conf file looks like so:

#--- start of atalkd.conf # The following three lines get # Appletalk zones going: ed0 -seed -phase 2 -net 1000-1200 -addr 1000.1 -zone "CR1" ed1 -seed -phase 2 -net 2000-2200 -addr 2000.1 -zone "CR2" ed2 -seed -phase 2 -net 3000-3300 -addr 3000.1 -zone "CR3" #--- end of atalkd.conf

Voila! Works like a charm, even with At-Ease for networks and ANAT toolkit! Collisions are now around the 2% mark.

See http://www.transit.hanse.de/netatalk/router.html for more detail on using Netatalk as a router.

FreeBSD does TCP/IP routing between those interfaces without any drama either.

also, check out http://3macs.nowonder.com/network/index.html for more macintosh-centric info.

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