Google DNS and DHCP clients



  • I want to move away from using my ISP's DNS servers and use Google's instead.  So I've set the following configuration:

    General Setup:

    • DNS IPs have been set to 8.8.8.8 and 8.8.4.4.

    • "Allow DNS server list to be overridden by DHCP/PPP on WAN" is unchecked

    • "Do not use the DNS Forwarder as a DNS server for the firewall" is checked

    DNS Forwarder:

    • DNS Forwarder is Enabled

    • "Register DHCP leases in DNS forwarder" is checked

    • "Register DHCP static mappings in DNS forwarder" is checked

    • All other options within DNS Forwarder are unchecked

    DHCP Server:

    • DHCP Server is Enabled

    • The DNS Servers section is not populated.

    So on my DHCP clients, when I check the settings the only DNS server configured is the LAN address of my pfSense box.  If I try to do a traceroute from my system on the LAN (with a DHCP lease), I get the following:

    host:~ user$ traceroute www.pfsense.org
    traceroute to www.pfsense.org (208.123.73.69), 64 hops max, 52 byte packets
     1  pfsense (192.168.0.1)  1.582 ms  0.750 ms  0.700 ms
     2  10.82.8.1 (10.82.8.1)  8.151 ms  8.342 ms  8.116 ms
     3  ip68-4-11-194.oc.oc.cox.net (68.4.11.194)  8.336 ms  7.643 ms  8.072 ms
    

    A couple of questions:

    • Is seeing this 10.82.8.1 IP address normal?  Is this just an internal IP address pfSense is using?

    • Why is my ISP's DNS IP coming up on ping#3 instead of one of the configured Google DNS IPs?



  • DNS simply translates a hostname to a IP address. Using a different DNS server does not mean the route to a certain IP address will be different.

    Answer to 1: probably an internal IP used by your ISP.
    Answer to 2: see above.


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