Documentation: GENDNS

Before you start

To update a record you need three things from us:

A hostname and zone, often gendns.uk
A username
A secret, which acts as the password

Your username and secret are tied to your GEN account, so that account must be active for GENDNS to work. Requests are rate limited, and addresses that abuse the service are blocked automatically.

Your IP address

Returns the public address we see you on, in whichever format suits your client. Use the f parameter to choose.

Plain text

https://www.gendns.uk/ip?f=text

195.195.195.1

JSON

https://www.gendns.uk/ip?f=json

{"ip":"195.195.195.1"}

XML

https://www.gendns.uk/ip?f=xml

<?xml version="1.0" encoding="UTF-8"?>
<root><ip>195.195.195.1</ip></root>

The update request

A single HTTPS GET updates your record. This is the URL every client on this page is built on.

https://www.gendns.uk/dns?h=testdns&u=123-123-123-123&i=195.195.195.1&p=q35yq35q3e5gq35gq35h&port=443

Parameter	Required	Description
`h`	Yes	The hostname to update, without the zone.
`u`	Yes	Your username.
`p`	Yes	Your secret.
`i`	No	The IP address to set. If omitted, we use the address the request came from.
`port`	No	A service port, 1 to 65535. If omitted or invalid, it is stored as 0.

Responses

The update request replies with a single line of plain text, compatible with the conventions most DDNS clients expect.

Response	Meaning
`good 195.195.195.1`	The record was updated to the address shown.
`nochg`	The address and port are unchanged, so nothing was done.
`nohost`	The hostname and secret do not match an active record.
`dnserr`	The update was accepted but could not be applied. Try again shortly, and raise a ticket if it persists.
`fail-0`	A required parameter (`h`, `u` or `p`) is missing.

Synology

Go to Control Panel, External Access, DDNS.
Click Add, then Customize Provider.

Set the service provider to GENDNS and the query URL to:

https://www.gendns.uk/dns?h=__HOSTNAME__&u=__USERNAME__&i=__MYIP__&p=__PASSWORD__

Save the provider, then add a DDNS entry using it with your hostname, username and secret.
Click Test Connection. The status should read Normal.

Synology DSM Edit DDNS dialogue showing the GEN provider, hostname testdns and status Normal

ddclient

Add the following to your ddclient.conf, replacing your_username, your_password and testdns with your own values.

protocol=dyndns2
use=web, web=https://www.gendns.uk/ip?f=text
server=www.gendns.uk
ssl=yes
login=your_username
password=your_password
testdns

Programmatic DNS

For high availability, failover and automation, GENDNS offers an API for managing zones and records directly.

Endpoint	Purpose
`getZone`	Retrieve information about a DNS zone.
`putZone`	Create or update a DNS zone.
`getRR`	Retrieve a specific resource record.
`putRR`	Create or update a resource record.

Example request

curl -X GET "https://api.gendns.uk/v1/getZone?zone=example.com&u=username&p=secret"

Replace username and secret with your own credentials. API access is enabled on request: contact us or raise a ticket with support, and we will send the full reference for each endpoint, including parameters and response formats.