NTP Pool DNS servers

To direct our millions of NTP users to an appropriate server we run a customized DNS server. Many of the instances are offered by volunteers around the world. This page provides more information if you are interested in providing a (virtual) server to be used for DNS services.

Requirements for hosting a server

The NTP Pool DNS server usually runs on Ubuntu LTS. Virtual machines work well but need to be KVM or BHyve based (not container-based), as our setup process needs full root access to a kernel.

Operating System

A minimal install of 64-bit (x86_64) Ubuntu LTS. Our software also works with Enterprise Linux and FreeBSD, but our automation is most tested with Ubuntu.

CPU

2-4 cores; any 64-bit CPU from the last decade will do a nice job.

RAM

Minimum 2GB; 3-4GB preferred if possible.

Disk space

12GB or more, again mostly to allow for system updates etc. There are no specific performance requirements for disk IO.

IP addresses

One routable IPv4 address, ideally also IPv6. If your network supports us announcing our anycast network then announcing our anycast prefixes is possible.

Bandwidth

Typically 10-30Mbit/second per server (3-5TB per month).

During certain times of the hour and day the rate goes up significantly for a few seconds. If you are in a region with limited DNS server coverage but can't serve that many requests, we can configure less traffic for a particular server.

Software

Regular DNS servers can't smartly respond with a "nearby" server out of several thousand and do so weighted, so we run a bit of quirky DNS software that can.

Firewall/security

Our system configuration includes firewall rules, so no external firewall is needed. In case you operate one and need to apply rules, the necessary ports are:

1. port 53 (UDP and TCP)
2. port 443 (DNS over HTTP, UDP and TCP)
3. port 22 (ssh)
4. port 8052 and 8053 (mTLS authenticated monitoring)
5. port 179 (for optional bgp setups)

Be sure to disable session tracking for port 53/udp if you do have a firewall.

Management

We do the day-to-day management of the system.

If you are interested in helping with this, please email ask@develooper.com.