SND

Minimal authoritative PTR (rDNS, reverse DNS) resolver with automatic generation of records.

WARNING: This piece of software is at a very early development stage and should be considered experimental. It only implements a minimal feature set to pass the RIPE automated DNS test and is by no means standard-compliant. Please don't run it in production.

Compilation

Golang 1.13.5 or later is officially supported. Before starting, make sure the GOROOT and GOPATH environment variables are set correctly and there is a go binary is in your PATH.

Linux

git clone https://github.com/Jamesits/SND.git
cd SND
./build.sh

Collect the binary in the build directory.

Other OSes

Other OSes except Windows are not tested because of the lack of resources available to me, though in theory it should run fine. You need to figure out how to build on these platforms on yourself.

Cross Compiling

Set the GOOS and GOARCH to the desired values and run build.sh.

Usage

Configure SND

Copy over the self-documented example config and tweak it for your own need. Please do not leave any example.com things in your own config. Remove what you don't need.

Currently no strict config file format checking is implemented -- you might crash the program if some important keys are missing.

Set up SND

In most cases you are going to need 2 servers (or one server with 2 different IP addresses if you don't care about availability issues). Copy the exact same config file to both servers and launch SND on both of them:

./snd -config path/to/config.toml

Or, if you prefer Docker:

docker run --rm -p 53:53 -p 53:53/udp -v config.toml:/etc/snd/config.toml:ro snd

Run a simple test using dig:

$ dig @localhost -x 192.0.2.1

; <<>> DiG 9.11.5-P4-5.1-Debian <<>> @localhost -x 192.0.2.1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50924
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;1.2.0.192.in-addr.arpa.      IN      PTR

;; ANSWER SECTION:
1.2.0.192.in-addr.arpa. 3600  IN      PTR     192.0.2.1.example.com.

Set up DNS records

You need at least 2 A or AAAA records pointing to each of your SND servers. You might need to set them up as glue records based on your actual config.

ns1.example.com.	3600	IN	A	192.0.2.1
ns2.example.com.	3600	IN	A	192.0.2.2

Set up PTR record delegation

Set up a domain object at your RIR like this.

domain:   <zone name>
descr:    <description>
admin-c:  <nic-handle for administrative contact>
tech-c:   <nic-handle for technical contact>
zone-c:   <nic-handle for zone contact>
nserver:  ns1.example.com
nserver:  ns2.example.com
mnt-by:   <your maintainer>
source:   RIPE

Detailed instructions are provided per RIR:

• AfriNIC
• ARIN
• APNIC
• LACNIC
• RIPE NCC

Notes:

• The smallest IP block sizes available for delegation differ
• Only RIPE NCC is currently tested because I cannot afford IP blocks from the other RIRs