DNSSeeder

This project is currently under active development and is in Beta state.

DNSSeeder exposes a list of known peers to any new peer joining the Karlsen network via the DNS protocol.

When DNSSeeder is started for the first time, it will connect to the karlsend node specified with the -s flag and listen for addr messages. These messages contain the IPs of all peers known by the node. DNSSeeder will then connect to each of these peers, listen for their addr messages, and continue to traverse the network in this fashion. DNSSeeder maintains a list of all known peers and periodically checks that they are online and available. The list is stored on disk in a json file, so on subsequent start ups the karlsend node specified with -s does not need to be online.

When DNSSeeder is queried for node information, it responds with details of a random selection of the reliable nodes it knows about.

It is written in Go (golang).

This project is currently under active development and is in Beta state.

Requirements

Latest version of Go (currently 1.17)

Getting Started

• Install Go according to the installation instructions here: http://golang.org/doc/install

• Ensure Go was installed properly and is a supported version:

• Launch a karlsend node for the DNSSeeder to connect to

go version
go env GOROOT GOPATH

NOTE: The GOROOT and GOPATH above must not be the same path. It is recommended that GOPATH is set to a directory in your home directory such as ~/dev/go to avoid write permission issues. It is also recommended to add ${GOPATH}/bin to your PATH at this point.

• Run the following commands to obtain dnsseeder, all dependencies, and install it:

git clone https://github.com/karlsen-network/dnsseeder ${GOPATH}/src/github.com/karlsen-network/dnsseeder
cd ${GOPATH}/src/github.com/karlsen-network/dnsseeder
go install .

• dnsseeder will now be installed in either ${GOROOT}/bin or ${GOPATH}/bin depending on your configuration. If you did not already add the bin directory to your system path during Go installation, we recommend you do so now.

To start dnsseeder listening on udp 127.0.0.1:5354 with an initial connection to working testnet node running on 127.0.0.1:

./dnsseeder -n nameserver.example.com -H network-seed.example.com -s 127.0.0.1 --testnet

You will then need to redirect DNS traffic on your public IP port 53 to 127.0.0.1:5354 Note: to listen directly on port 53 on most Unix systems, one has to run dnsseeder as root, which is discouraged.

Setting up DNS Records

To create a working set-up where the DNSSeeder can provide IPs to karlsend instances, set the following DNS records:

NAME                        TYPE        VALUE
----                        ----        -----
[your.domain.name]          A           [your ip address]
[ns-your.domain.name]       NS          [your.domain.name]