nubits-seeder
===============

nubits-seeder is a crawler for the nubits network, which exposes a list
of reliable nodes via a built-in DNS server.

Features:
* regularly revisits known nodes to check their availability
* bans nodes after enough failures, or bad behaviour
* accepts nodes down to v0.9.11.5 to request new IP addresses from,
  but only reports good post-v0.9.11.5 nodes.
* keeps statistics over (exponential) windows of 2 hours, 8 hours,
  1 day and 1 week, to base decisions on.
* very low memory (a few tens of megabytes) and cpu requirements.
* crawlers run in parallel (by default 96 threads simultaneously).

USAGE
-----

Assuming you want to run a dns seed on dnsseed.example.com, you will
need an authorative NS record in example.com's domain record, pointing
to for example vps.example.com:

$ dig -t NS dnsseed.example.com

;; ANSWER SECTION
dnsseed.example.com.   86400    IN      NS     vps.example.com.

On the system vps.example.com, you can now run dnsseed:

./dnsseed -h dnsseed.example.com -n vps.example.com

If you want the DNS server to report SOA records, please provide an
e-mailadres (with the @ part replaced by .) using -m.

RUNNING AS NON-ROOT
-------------------

Typically, you'll need root privileges to listen to port 53 (name service).

One solution is using setcap (Linux only) to give the executable permission
to use a privileged port:

sudo setcap 'cap_net_bind_service=+ep' ./dnsseed