dn42

Since April 2025, I’ve been running a dn42 network in order to learn computer networking concepts like IP, BGP, and DNS.

Overview

• AS number: AS4242421919
• IPv4 range: 172.21.89.64/27
• IPv6 range: fd11:4514:1919::/48

You can view this AS on the dn42 registry explorer.

All nodes are hosted on Vultr. I use BIRD 2 as the BGP daemon, WireGuard for tunneling, and ZeroTier for internal meshing. Through dnsmasq, each node is also a simple DNS resolver that forwards requests to the dn42 DNS anycast service.

Peering

To peer, you can contact me via any method listed on my homepage. Peering policy (in RFC 2119 parlance):

• Each node must only have one peering per AS.
• Tunneling must be done through WireGuard.
• Multiprotocol BGP (MP-BGP) is recommended.
  • With MP-BGP, peering through IPv6 exclusively is recommended.
• Link-local addresses should be used for IPv6 peering.
• All incoming routes are checked with RPKI.

Please include all the following information in your initial request, so I can set up the peering without extra back and forth.

• Your AS number
• A way to reach you for further correspondence
• For each peering:
  • The node you want to peer with
  • Your node’s WireGuard endpoint (IP/hostname + port)
  • Your node’s WireGuard public key
  • Your node’s IPv6 address over the tunnel (link-local recommended)
  • Your node’s dn42 IPv4 address (only if you can’t do MP-BGP)

All the information you will need to peer with me is listed below. All WireGuard ports are :4[xxxx] where [xxxx] is the last 4 digits of your AS number.

Nodes

Currently there are two nodes in this network.

US East / New Jersey (ewr1)

US West / Silicon Valley (sjc1)