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Barracuda CloudGen Firewall

This Firmware Version Is End-Of-Support

Documentation for this product is no longer updated. Please see https://campus.barracuda.com/doc/71862301/ for further information on our EoS policy.

How to Configure DHCP with Dynamic DNS

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Configure dynamic DNS updates for the Barracuda NG Firewall DHCP service. The DDNS update style is evaluated once after reading the dhcpd.conf file, not each time a client is assigned an IP address, so the same DNS update style is used for all clients.

Before You Begin

Before configuring dynamic DNS, enable advanced pool configuration in the DHCP service setup. For more information, see How to Configure Advanced DHCP Settings.

Configure Dynamic DNS

  1. Open the DHCP Enterprise Configuration page (Config > Full Config > Box > Virtual Servers > your virtual server > Assigned Services > DHCP-Service).
  2. In the left menu, expand the Configuration Mode section and click Advanced View.
  3. In the left menu, select Dynamic DNS.
  4. Click Lock.
  5. Select whether or not to use a DNS Update Scheme.
    • When selecting interim choose an option from the Client Updates list.

      The DHCP server does not necessarily always update both the A and the PTR records. The FQDN (fully qualified domain name) option includes a flag which, when sent by the client, indicates that the client wishes to update its own A record. In that case, the server can be configured either to honor the client's intentions or ignore them. This is done with the statement allow client-updates; or the statement ignore client-updates. By default, client updates are ignored.

  6. In the Zone Keys table, click + and add the HMAC-MD5 keys for the DNS zones.
  7. In the DNS Zones table, click + and add the DNS zones. 
  8. Specify the Zone Type. You can select:
    • Forward (default) – The hostname is looked up.
      • Enter the network of the forward lookup in the Forward Zone Name field.
    • Reverse – The IP address is looked up.
      • Enter the network of the reverse lookup in the Reverse Lookup Net/Netmask fields.
    • Both – IP address and hostname are looked up.
      • Enter the network of the forward and reverse lookup in the Forward Zone Name and Reverse Lookup Net/Netmask fields.
  9. Enter the DNS Server IP address.
  10. Select the Authentication Key for the zone that was entered in the Zone Keys table.
  11. Click OK.
  12. Click Send Changes and Activate.
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