mirror of
https://github.com/vyos/vyos-documentation.git
synced 2025-10-26 08:41:46 +01:00
Merge pull request #1561 from abukharov/feature/dhcp-ddns
dhcp-server: ddns: T6773: DDNS configuration documentation
This commit is contained in:
Daniil Baturin
GitHub
commit
0858fe7233
@ -166,6 +166,187 @@ Unifi controller at ``172.16.100.1`` to clients of that subnet.
|
||||
'172.18.201.0/24' option vendor-option ubiquiti '172.16.100.1'
|
||||
|
||||
|
||||
Dynamic DNS Update (RFC 2136)
|
||||
-----------------------------
|
||||
|
||||
VyOS DHCP service supports RFC-2136 DDNS protocol. Based on DHCP lease change
|
||||
events, DHCP server generates DDNS update requests (defines as NameChangeRequests
|
||||
or NCRs) and posts them to a compliant DNS server, that will update its name
|
||||
database accordingly.
|
||||
|
||||
VyOS built-in DNS Forwarder does not support DDNS, you will need an external DNS
|
||||
server with RFC-2136 DDNS support.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update
|
||||
|
||||
Enables DDNS globally.
|
||||
|
||||
**Behavioral settings**
|
||||
|
||||
These settings can be configured on the global level and overridden on the scope
|
||||
level, i.e. for individual shared networks or subnets. See examples below.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update send-updates [ enable
|
||||
| disable ]
|
||||
|
||||
If set to ``enable`` on global level, updates for all scopes will be enabled,
|
||||
except if explicitly set to ``disable`` on the scope level. If set to ``disable``,
|
||||
updates will only be sent for scopes, where ``send-updates`` is explicity
|
||||
set to ``enable``.
|
||||
|
||||
This model is followed for a few behavioral settings below: if the option is
|
||||
not set, the setting is inherited from the parent scope. You can override the
|
||||
parent scope setting by setting the option explicitly.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update override-no-update [ enable
|
||||
| disable ]
|
||||
|
||||
VyOS will ignore client request not to update DNS records and send DDNS
|
||||
update requests regardless.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update override-client-update [ enable
|
||||
| disable ]
|
||||
|
||||
VyOS will override client DDNS request settings and always update both
|
||||
forward and reverse DNS records.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update update-on-renew [ enable
|
||||
| disable ]
|
||||
|
||||
Issue DDNS update requests on DHCP lease renew. In busy networks this may
|
||||
generate a lot of traffic.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update conflict-resolution [ enable
|
||||
| disable ]
|
||||
|
||||
Use RFC-4703 conflict resolution. This algorithm helps in situation when
|
||||
multiple clients reserve same IP addresses or advertise identical hostnames.
|
||||
Should be used in most situations.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update replace-client-name [ never
|
||||
| always | when-present | when-not-present ]
|
||||
|
||||
* **never**: use the name sent by the client. If the client didn't provide any,
|
||||
do not generate one. This is the default behavior
|
||||
|
||||
* **always**: always generate a name for the client
|
||||
|
||||
* **when-present**: replace the name the client sent with a generated one, if
|
||||
the client didn't send any, do not generate one
|
||||
|
||||
* **when-not-present**: use the name sent by the client. If the client didn't
|
||||
send any, generate one for the client
|
||||
|
||||
The names are generated using ``generated-prefix``, ``qualifying-suffix`` and the
|
||||
client's IP address string.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update generated-prefix <prefix>
|
||||
|
||||
Prefix used in client name generation.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update qualifying-suffix <suffix>
|
||||
|
||||
DNS suffix used in client name generation.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update ttl-percent <0-100>
|
||||
|
||||
TTL of the DNS record as a percentage of the DHCP lease time.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update hostname-char-set
|
||||
<character string>
|
||||
|
||||
Characters, that are considered invalid in the client name. They will be replaced
|
||||
with ``hostname-char-replacement`` string.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update hostname-char-replacement
|
||||
<character string>
|
||||
|
||||
Replacement string for the invalid characters defined by ``hostname-char-set``.
|
||||
|
||||
**TSIG keys definition**
|
||||
|
||||
This is the global list of TSIG keys for DDNS updates. They need to be specified by
|
||||
the name in the DNS domain definitions.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update tsig-key <key-name>
|
||||
algorithm <algorithm>
|
||||
|
||||
Sets the algorithm for the TSIG key. Supported algorithms are ``hmac-md5``,
|
||||
``hmac-sha1``, ``hmac-sha224``, ``hmac-sha256``, ``hmac-sha384``, ``hmac-sha512``
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update tsig-key <key-name>
|
||||
secret <key-secret>
|
||||
|
||||
base64-encoded TSIG key secret value
|
||||
|
||||
**DNS domains definition**
|
||||
|
||||
This is global configuration of DNS servers for the updatable forward and reverse
|
||||
DNS domains. For every domain multiple DNS servers can be specified.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update [forward|reverse]-domain
|
||||
<domain-name> key-name <tsig-key-name>
|
||||
|
||||
TSIG key used for the domain.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update [forward|reverse]-domain
|
||||
<domain-name> dns-server <number> address <ip-address>
|
||||
|
||||
IP address of the DNS server.
|
||||
|
||||
.. cfgcmd:: set service dhcp-server dynamic-dns-update [forward|reverse]-domain
|
||||
<domain-name> dns-server <number> port <port>
|
||||
|
||||
UDP port of the DNS server. ``53`` is the default.
|
||||
|
||||
**Example:**
|
||||
|
||||
Global configuration you will most likely want:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
set service dhcp-server dynamic-dns-update send-updates enable
|
||||
set service dhcp-server dynamic-dns-update conflict-resolution enable
|
||||
|
||||
Override the above configuration for a shared network NET1:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
set service dhcp-server shared-network-name 'NET1' dynamic-dns-update replace-client-name when-not-present
|
||||
set service dhcp-server shared-network-name 'NET1' dynamic-dns-update generated-prefix ip
|
||||
set service dhcp-server shared-network-name 'NET1' dynamic-dns-update qualifying-suffix mybigdomain.net
|
||||
|
||||
And in a subnet within the same shared network:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
set service dhcp-server shared-network-name 'NET1' subnet '172.18.201.0/24' dynamic-dns-update qualifying-suffix mydomain.net
|
||||
|
||||
Configure TSIG keys:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
set service dhcp-server dynamic-dns-update tsig-key mydomain-net algorithm hmac-sha256
|
||||
set service dhcp-server dynamic-dns-update tsig-key mydomain-net secret eWF5YW15bGl0dGxla2V5IQ==
|
||||
set service dhcp-server dynamic-dns-update tsig-key reverse-172-18-201 algorithm hmac-sha256
|
||||
set service dhcp-server dynamic-dns-update tsig-key reverse-172-18-201 secret eWF5YW15YW5vdGhlcmxpdHRsZWtleSE=
|
||||
|
||||
Configure DDNS domains:
|
||||
|
||||
.. code-block:: none
|
||||
|
||||
set service dhcp-server dynamic-dns-update forward-domain mydomain.net key-name mydomain-net
|
||||
set service dhcp-server dynamic-dns-update forward-domain mydomain.net dns-server 1 address '172.18.0.254'
|
||||
set service dhcp-server dynamic-dns-update forward-domain mydomain.net dns-server 1 port 1053
|
||||
set service dhcp-server dynamic-dns-update forward-domain mydomain.net dns-server 2 address '192.168.124.254'
|
||||
set service dhcp-server dynamic-dns-update forward-domain mydomain.net dns-server 2 port 53
|
||||
set service dhcp-server dynamic-dns-update forward-domain 201.18.172.in-addr.arpa key-name reverse-172-18-201
|
||||
set service dhcp-server dynamic-dns-update reverse-domain 201.18.172.in-addr.arpa dns-server 1 address '172.18.0.254'
|
||||
set service dhcp-server dynamic-dns-update reverse-domain 201.18.172.in-addr.arpa dns-server 1 port 1053
|
||||
set service dhcp-server dynamic-dns-update reverse-domain 201.18.172.in-addr.arpa dns-server 2 address '192.168.124.254'
|
||||
set service dhcp-server dynamic-dns-update reverse-domain 201.18.172.in-addr.arpa dns-server 2 port 53
|
||||
|
||||
|
||||
High Availability
|
||||
-----------------
|
||||
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user