Dynamic DNS¶
VyOS is able to update a remote DNS record when an interface gets a new IP address. In order to do so, VyOS includes ddclient, a Perl script written for this only one purpose.
ddclient uses two methods to update a DNS record. The first one will send updates directly to the DNS daemon, in compliance with RFC 2136. The second one involves a third party service, like DynDNS.com or any other similar website. This method uses HTTP requests to transmit the new IP address. You can configure both in VyOS.
Configuration¶
RFC 2136 Based¶
Example¶
- Register DNS record
example.vyos.ioon DNS serverns1.vyos.io - Use auth key file at
/config/auth/my.key - Set TTL to 300 seconds
[email protected]# show service dns dynamic
interface eth0.7 {
rfc2136 VyOS-DNS {
key /config/auth/my.key
record example.vyos.io
server ns1.vyos.io
ttl 300
zone vyos.io
}
}
This will render the following ddclient configuration entry:
#
# ddclient configuration for interface "eth0.7":
#
use=if, if=eth0.7
# RFC2136 dynamic DNS configuration for example.vyos.io.vyos.io
server=ns1.vyos.io
protocol=nsupdate
password=/config/auth/my.key
ttl=300
zone=vyos.io
example.vyos.io
Note
You can also keep different DNS zone updated. Just create a new
config node: set service dns dynamic interface <interface> rfc2136
<other-service-name>
HTTP based services¶
VyOS is also able to use any service relying on protocols supported by ddclient.
To use such a service, one must define a login, password, one or multiple hostnames, protocol and server.
custom DynDNS provider is used the protocol used for communicating
to the provider must be specified under <protocol>. See the embedded
completion helper for available protocols.custom DynDNS provider is used the <server> where update
requests are being sent to must be specified.Example:¶
Use DynDNS as your preferred provider:
set service dns dynamic interface eth0 service dyndns
set service dns dynamic interface eth0 service dyndns login my-login
set service dns dynamic interface eth0 service dyndns password my-password
set service dns dynamic interface eth0 service dyndns host-name my-dyndns-hostname
Note
Multiple services can be used per interface. Just specify as many serives per interface as you like!
Running Behind NAT¶
By default, ddclient will update a dynamic dns record using the IP address directly attached to the interface. If your VyOS instance is behind NAT, your record will be updated to point to your internal IP.
ddclient has another way to determine the WAN IP address. This is controlled by: