DNS Server Return/Lookup when trapped



  • i am using DHCP which sets the DNS server as pfsense, for some clients like andoid and windows (particularly with antivirus/firewalls) they set their own DNS overrides. e.g. comodo and avast

    I created a NAT Rule;

    Interface: LAN
    Protocol: TCP/UDP
    Source: LAN Net
    Src Port: *
    Dest: !pfsense
    Dest Port: 53
    NAT IP: LAN Net
    NAT Port: 53

    I block 53 from the WAN/VPNs and the rule works i.e. all PCs can resolve even with DNS overrides.

    Only one small thing i notice.
    When using nslookup to either resolve the host or the IP, the server is returned as unknown
    e.g.
    nslookup google.com
    Server: Unknown
    Address: 156.154.70.22
    Non-authoritative Answer
    Name: google.com
    Address: 172.217.19.206

    If the DNS is set to pfsense, the server name and address will be pfsense and the address of pfsense

    Am i able to return the DNS server name via a rule (even if trapped) or should i just ignore?


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