DNS

The domain name system - short DNS - provides a resolution of the domain (for example geti2p.net) into an IP address (for example 81.7.7.63). In I2P, the IP addresses of the participating routers are known, but not which router offering services. Instead, I2P services (for example eepsites) are linked to destinations. This means I need the appropriate destination to call an I2P service. So you could say that the IP address of a Web site in i2P is the destination of an eepsite.

An analogy to the domain name system, would be the phone book: to call someone, you need the phone number. If you do not know the phone number, you look in the phone book. The phone book would be a name registry in I2P (Expert Info: In the Clearnet, the phone book would be a DNS server).

How to get to the destinations for the corresponding services?

The own I2P router itself also leads a list of domain names and destinations. These are often stored in the so-called hosts.txt. This means that in case of resolution the router look at the local list. This local list of domain names and destinations is also referred to as an address book.

Where do you get this lists?

There are several registries in I2P. These registries then keep a list of domain names and destination. The router regularly checks in the background whether the registries offer new domain names. If there is new the router gets the domain names with the destinations and stores them locally. The DNS in i2P can be described as decentralized. So there is no central instance that keeps the domain names and the destinations ready. For example, if a registry is down, you once saved the entries that locally stored at this point and, secondly, you can easily use multiple registries. This means it can be without problems one or more registries offline, as there are several. Often it is so that the registries exchange the lists with each other - or the operator of a service registers and shares their destination with more than one registry. The second reason why you can describe the DNS in i2P as a decentralized is that there is no instance that can prevent the registry. Even if you broke a registry to delete an entry, you still have the entry yourself and other registries. There are many registries and everyone can actually open their own. Here is a selection of registries:

Registries

Site	Operator	Reliable
stats.i2p	This site is operated by zzz, one of the main developers of I2P.	Yes
reg.i2p	Developers of i2pd	Yes
inr.i2p	Unknown	Probably yes
identiguy.i2p	Unknown	Probably yes
isitup.i2p	Unknown	Probably yes
i2pjump.i2p	Unknown	Probably yes

It is also possible to provide a list of domain names and destinations without being acting as a registry. A selection of such services:

Anbieter von Listen mit Domainnamen und Destinations ohne Registrierungsfunktion

Site	Operator	Info	Reliable
http://i2p-projekt.i2p/hosts.txt	This list operated by the I2P project.	This list contains long existing Eepsites and serves to provide a "basic list".	Yes
http://notbob.i2p/hosts.txt	Notbob		Yes

What are Jump URLs (Jump Services)?

Sometimes it happens that the router does not know the destination of a domain. This may be because the domain is new and the router has not yet updated the list of domain names and destinations. But it may also be that the domain name is only registered with a registration site and the router does not get information from exactly this registry. No matter what the reason is, in this case, Jump Services are used. The Jump Service looks to yourself in the address book - so in its own list of domain names and destinations and returns the appropriate destination to the router. Of course, it may happen that the Jump Service does not know the domain. In this case, it is advisable to try another Jump Service. Since Jump Services needs to know many domains and have a large list accordingly, most Jump Services are operated by registries, which must already have a large list due to their function as a registry. A selection of Jump Services:

Jump services

URL	Info
http://stats.i2p/cgi-bin/jump.cgi?a=	This site is operated by ZZZ, one of the main developers of I2P.
http://i2pjump.i2p/jump/	This page collects the address books from different pages and provides them.
http://notbob.i2p/cgi-bin/jump.cgi?q=	This site is operated by NotBob.
http://inr.i2p/jump/	It is not known who operates this page. She seems to be trustworthy.
http://reg.i2p/jump/	This site is operated by the developers of I2PD.

For me there are several address books. Which should I use?

In general, you should use the router address book. In this, all entries of registries are also loaded. The Private Address Book is private. This means it is shared with no one others! It can be used, for example, to access private services (expert info: for example SSH or FTP). Normally, you do not need them. The local address book should be used for services that you operate. For example, if you operate an Eepsite (for example a private blog) or the like, you can enter them there. However, it is not necessary to enter them there. Normally, you do not need this address book. The local address book is automatically intrigued in the Router Address Book (merge). The public address book is only available for experts and experiencing eepsite operators. It can be used to publish a list of domain names and destinations yourself.

Which registries should I use?

The advantage, but also the disadvantage of registrations is that everyone can operate a registry. The advantage is that, for example, there are always enough registries. The advantage is also that there are always enough registries. The disadvantage, however, is that even cheats can operate registries. So these could then specify a false destination to a domain. As a result, you could know without it to stumble on a fraudulent side. Therefore, in advance, one should explore how trustworthy is a registry. This is also the reason that only a few registries are entered in the router by default.

Glossary

Glossary

Term	Meaning
IP address	In order for computers to be able to communicate (talk) with one another, they need names like us humans. The difference, however, is that the computers do not have names, but IP addresses. In principle, every computer that is connected to the Internet has an IP address. With this he can be clearly identified. So an IP address is used so that computers know who is talking to.
Eepsite	A website in the I2P network
I2P Router	Die lokale Software, welche auf dem Computer installiert ist, damit man Zugang zum I2P Netzwerk bekommt. (z. B. Java I2P oder I2Pd)
I2P service	A service that is offered in the I2P network. These can be eepsites, chat servers, but also games.
Destination	An IP address in the I2P network. The difference, however, is that you cannot find out the actual IP address with the destination. As a result, his own identity cannot be determined by others. The destination is usually in the form of a Base32 (long text that ends with ".b32.i2p") or Base64 (long text that even contains ~ characters).
Expert info	Additional information, which is not important for understanding the text.
Clearnet	In contrast to the I2P network, the Clearnet is the "normal" Internet.
local	on your own computer
decentralized	Decentralized means that it is not subordinate to any central authority (government, private person, company) that is bundled in one place.
I2Pd	I2P router written in C ++. In contrast to the "normal" Java I2P router, I2Pd requires fewer system resources (RAM, CPU, ...).
address book	There is a list of domain names and corresponding destinations. This collection on your I2P router is also known as an address book.

External sites

• https://geti2p.net/en/docs/naming
• https://geti2p.net/de/faq