This describes the global, interconnected, Chaosnet. If you just want to set up a local Chaosnet, please see here for instructions.

To see what hosts are up on the global Chaosnet, see here. To see who is logged in on Chaosnet hosts, see here.

A Chaosnet bridge runs on (the IP, IPv6, and Chaos) host MX12.Victor.SE, accessible by TLS on port 42042, or using IP protocol 16 (over IPv4 or IPv6), as Chaos host 3040. Another bridge is running on Chaos.Swenson.ORG (also accessible as Router.Chaosnet.NET), accessible by TLS on port 42042. For convenience, Router.Chaosnet.NET has both the IPs of MX12.Victor.SE and Chaos.Swenson.ORG.

Both bridges

• route packets between connected networks,
• send and process Chaosnet routing (RUT) packets to connected networks (and CHUDP hosts), and
• respond to the contact names STATUS, TIME, UPTIME and DUMP-ROUTING-TABLE, among others.

See here (or MIT AI Memo 628) for more details about the protocols.

To connect to the “global” Chaosnet, you need to register a compatible Chaosnet address. In the normal case, you should connect using Chaos-over-TLS.

• To connect using Chaos-over-UDP, you need a stable IP address and a compatible Chaosnet address, and if you connect directly to MX12 using CHUDP, I need to open the firewall there.
• To connect using Chaos-over-TLS, you do not need a stable IP address, but you do need a certificate issued by my Certificate Authority (see here for instructions).

I strongly recommend that you join the chaosnet-hackers[at]its.victor.se mailing list.

Set up a cbridge to handle your local network. Tell Björn the things as below about your cbridge host, and also ask Björn for a separate subnet to use. Do NOT add all your local hosts to subnet 6, but only the cbridge (whose address you get from Björn). See configuration examples below.

To add DNS info (which is mandatory), send Björn

• the names of the hosts, including domains (but do not just invent domains - see below),
• what kinds of hosts they are (ITS? Lambda/Explorer/Symbolics Lisp machine? TOPS-20? cbridge? etc), and
• their Chaosnet addresses on your subnet.

I'm thinking about this. The old WHO-AM-I and TI-WHO-AM-I protocols are not quite sufficient, and full-blown DHCP is a bit overkill.

You can ask to get added to (a subdomain of) Chaosnet.NET.

I am very reluctant to¹⁾ add Chaosnet DNS info for domains none of us are in control of, since they might discover and complain, with possible legal and financial results.

After joining the Global Chaosnet, you may need to change the Chaosnet addresses of your local hosts. How you do that of course depends on what kind of operating system and emulator you use.

• For PiDP-10 systems, which typically run a simh KA emulator, see the documentation and look for “SET CH NODE=”.
• For ITS under klh10, you need to change the `myaddr` parameter of `devdef chaos`.
• For CADR systems under usim, you may need to change the `bridgechaos` config (but this info may be outdated).

• For TOPS-20, edit `SYSTEM:CHAOSNET.ADDRESS` (no changes are needed for the emulator since TOPS-20 uses Chaos-over-IP).
• For ITS, you need to edit `SYSHST;H3TEXT` and run `:SYSHST;H3MAKE`, ideally *before* you change the emulator configuration (since ITS might not like it if it doesn't find the name of its address).

You also need to make sure the cbridge configuration matches the changes you do: typically you change `link chudp` (e.g. for PiDP-10 or usim systems) and `link ip` (for TOPS-20) lines.

For configuration examples, please see here.

The following subnets (in octal) are used/registered or special. For historical use, see AI:SYSHST;HSTNET >.

To generate host tables in various form (when you can't use DNS), try this tool. On the Chaosnet, you can also use the HOSTAB server at HOSTAB.Chaosnet.NET.

Note that while there are technically 255 subnets (excluding 0), only 172 (octal) different nets fit in a routing table pkt, and the DUMP-ROUTING-TABLE protocol only lists subnets up to 172.

Special: the TI-WHO-AM-I protocol broadcasts on that subnet to find out its address, and it is probably often default for old Real machines, e.g. Lispms. Previously used for the Chaos-over-Ethernet at Update, because the old Symbolics 3600 had address 401.

This is for hosts connected to MX12 by Chaosnet over UDP (CHUDP), IP (v4/v6) or over TLS, mainly ITS hosts and cbridge processes.

Side note: MX12 is named after MX-11, which was a Chaos gateway at MIT; one of its addresses was 3040 which is on net 6; address 3040 is the default for routes in ITS, see SYSTEM;CHAOS >.

Special: Default subnet for LMI machines; 3412 used by LMI machines for “Amnesia” (hosts that don't know their address). BVs home network, over Ethernet, IP, UDP, and Unix sockets.

Allocated for Bogodyne Metatechnics LLC.

AMS' home network (AMS.Chaosnet.NET).

Eric Swenson's network.

Michael Wyrick's network.

John Floren's network.

Used by SJ.GEWT.NET (a long time ago now).

Phillip Porch's network.

A second subnet for BV.

Sanyal Supratim's network.

Mete Balci's network.

In order to minimise address collisions and routing problems, this subnet has been reserved as a private, non-routed subnet. No routing information about that subnet should be sent outside that subnet, no packets from that subnet should be sent to other subnets, and any packets received from that subnet on another subnet should be dropped.