You want to join dn42, but you don't know where to start. This guide gives general guidelines about dn42 and routing in general, but it assumes that you are knowledgeable with routing.
# Requirements
- you have at least one router running 24/7. Any Linux or BSD box can be turned into a router. If your home router runs OpenWRT, you might consider using it for dn42.
- your router is able to establish network tunnels over the Internet (GRE, OpenVPN, IPSec, Tinc...). Beware, your network operator might filter this kind of traffic, e.g. in schools or universities.
- you are generally knowledgable with networking and routing (i.e. you've heard about BGP, IGP, forwarding, and you're willing to configure a BGP router such as Quagga or Bird)
# Formalities
Don't worry, it's not as tedious as registering with a RIR ;)
## Subscribe to the mailing list
This is important, as it allows to stay up-to-date on best practices, new services, security issues...
You must create several objects in the registry. The recommended method is to use the [web interface](https://io.nixnodes.net/?registry), but you may still work directly with the [monotone repository](/services/Whois#monotone).
This example assumes that your name is `<FOO>`, part of an organisation called `<FOO-ORG>` (for instance, your hackerspace). Obviously, these should be replaced by the appropriate values in all examples below.
We will create several types of objects: **maintainer** objects, which have an associated password and allow you to authenticate so that you can edit your own objects; **person** objects, which describe people or organisations and provide contact information; and finally, all other objects, which are resources (AS number, IP subnet, DNS zone, etc).
- choose a password, and don't forget it. **Note:** even though the field is named `sha512-pw`, you must enter *your password* directly, *not* the sha512 of your password.
- you may provide additional ways of contacting you, using one or more `contact` field. For instance `xmpp:luke@theforce.net`, `irc:luke42@hackint`, `twitter: TheGreatLuke`.
Your AS number can be chosen arbitrarily in the dn42 ASN space, look at the `as-block` objects. The historic ASN space is around 64600-64855 and 76100-76200. Starting from June 2014, **you must allocate your AS number in the new 4242420000-4242423999 range**.
If you intend to use an ASN outside of the native dn42 ranges, please check that it doesn't clash with the [Freifunk AS-Numbers] (http://wiki.freifunk.net/AS-Nummern) or other networks (ChaosVPN, etc). For a list of ASN currently announced in dn42, see [this map](http://nixnodes.net/dn42/graph/) or [this list](http://dataviz.polyno.me/lastseen/).
You may choose your network prefix in one of the currently open netblocks. You can get a list of unassigned subnets here: [Open Netblocks](http://dn42.netrik.de/), please mind the allocation guideline. There is also a [graphical visualisation of the assigned ranges](http://dataviz.polyno.me/dn42-netblock-visu/registry.html).
The current guideline is to allocate a /27 or smaller by default, keeping space for up to a /26 if possible. Don't allocate more than a /25 worth of addresses and please **think before you allocate**: If you are going to have 2-3 servers and two VPN-spaces, a /28 is enough to suit your needs. Same will go for most home-networks. This is not public internet, but our IPv4-space is valuable too! If you need a /24 or larger, please ask in the IRC chan or on the mailing list.
For example, if there is no /27 free, you can split up a /26 into two /27. If you are looking for a /27 but there are none showing in the Open Netblocks tool, instead pick one of the /26 and click Take it!
When registering your inetnum, instead of writing 172.2x.xxx.0-172.2x.xxx.63 then you can write 172.2x.xxx.0-172.2x.xxx.31. This will get you a /27 and save our IP space for others.
**Note:** Reverse DNS works with _any_ prefix length, as long as your [recursive nameserver](/services/DNS) supports [RFC 2317](https://www.ietf.org/rfc/rfc2317.txt). Don't go for a /24 _just to have RDNS_.
If you want to register an [IPv6 prefix](/FAQ#frequently-asked-questions_what-about-ipv6-in-dn42), you can create an `inet6num` object. A single /48 allocation in [ULA space](https://www.sixxs.net/tools/grh/ula/) will likely provide more than enough room for all devices you will ever connect. Some people use “vanity” prefixes like fd42:_xyz_::/48 instead of the fully standard-conformant pseudorandom ones.
If you plan to announce your prefixes in dn42, which you probably want in most cases, you will also need to create a `route` object for ipv4 prefixes and a `route6` object for ipv6 prefixes. This information is used for ROA checks (route origin authorization). If you skip this step, your network will probably get filtered by some peers. Many people enforce ROA checks to prevent (accidental) hijacking of other people's prefixes.
In dn42, there is no real distinction between peering and transit: in most cases, everybody serves as an upstream provider to all its peers. Note that if you have very slow connectivity to the Internet, you may want to avoid providing transit between your peers, which can be done by filtering or prepending your ASN. For the sake of sane routing, try to peer with people on the same continent to avoid inefficient routing, <50msisagoodruleofthumb.YoucanalsolookintoBirdcommunitiesifyouareusingBirdtomarkthelatencyforthe [link](/howto/Bird-communities).
It will let you find people to peer with. You can then contact them on IRC or by email. In case you're really at loss, you can also ask for peers on the mailing list.
You need a routing daemon to speak BGP with your peers. People usually run Quagga or Bird, but you may use anything (OpenBGPD, XORP, somebody even used an old [hardware router](bgp-on-extreme-summit1i) ). See the relevant [FAQ entry](/FAQ#frequently-asked-questions_what-bgp-daemon-should-i-use).
Some [documentation of the old wiki] (http://dn42.volcanis.me/initenv/wiki/HowToPeer.html) might still be handy, but remember that everything there is terribly outdated.
Don't hesitate to provide interesting services, but *please*, document them on the wiki! Otherwise, nobody will use them because nobody can guess they even exist.
