translate the ip address 8.8.8.8 to 192.168.1.53

Started by schtebo, November 27, 2019, 08:31:35 AM

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Hi,
is it possible to translate the ip address 8.8.8.8 to 192.168.1.53? and how can i do that?
192.168.1.53 is my internal dns-server.
my goal is, that all queries send to 8.8.8.8 will be answered by my own dns-server. :)
thank you + br
schtebo

Hi,
in System > Settings > General yo can enter 192.168.1.53 as your DNS server and uncheck "Allow DNS server list to be overridden by DHCP/PPP on WAN"

After that, you can allow OPNSense be your DNS server so every query will be forwarded to your chosen IP.

November 27, 2019, 11:54:51 AM #2 Last Edit: November 27, 2019, 12:50:16 PM by hbc
Sure, it is a pretty simple redirect.

Just set up a forward rule 'Firewall: NAT: Port Forward' and forward src any, dst host 8.8.8.8 port 53 to 192.168.1.53 port 53.

Since there exist more public dns servers (8.8.4.4, 1.1.1.1, 9.9.9.9 and many more), I would modify your redirect like this:


  • Create alias with your dns servers (My_DNS).
  • Create redirect rule with:
    redirect src any, dst host NOT My_DNS port 53 to 192.168.1.53 port 53 (Maybe My_DNS works as redirect target? Did not test it)

With this rules, clients already using your dns are not redirected. Every client using any other dns server than defined in My_DNS, gets redirected to yours.
Intel(R) Xeon(R) Silver 4116 CPU @ 2.10GHz (24 cores)
256 GB RAM, 300GB RAID1, 3x4 10G Chelsio T540-CO-SR

Quote from: muchacha_grande on November 27, 2019, 11:49:28 AM
Hi,
in System > Settings > General yo can enter 192.168.1.53 as your DNS server and uncheck "Allow DNS server list to be overridden by DHCP/PPP on WAN"

After that, you can allow OPNSense be your DNS server so every query will be forwarded to your chosen IP.

This just affects the DNS server, OPNsense uses itself. He wants to redirect his clients to his DNS server. And I don't think his provider assigns Google DNS 8.8.8.8 as dns  ;)
Intel(R) Xeon(R) Silver 4116 CPU @ 2.10GHz (24 cores)
256 GB RAM, 300GB RAID1, 3x4 10G Chelsio T540-CO-SR