Linux machines not resolving manual added DNS entries in pfsense



  • Hello,

    I have pfsense 2.4.4 running. It is working okay. The only issue we are having is that Linux machines do not resolve the dns addresses added in DNS Resolver in pfsense. Windows machines do not have a problem with that.
    For example:
    Host Overrides Parent domain or host IP to return to host Desciption
    cpanel smart.az 192.168.2.211 cpanel.smart.az
    pfsense smart.az 192.168.4.1 pfsense.smart.az
    vcenter smart.local 192.168.2.100 vcenter.smart.az

    Linux output:
    ping: cpanel.smart.az: Name or service not known



  • Are the Linux machine using pfSense for DNS? That's the only way it works. If they can't resolve the same hosts that your Windows clients can easily resolve, then they're not using the same DNS.



  • Both Windows and Linux machines gets the same dns addresses from pfsense. Both can access websites on internet flawlessly.



  • You're assuming this or you actually checked? Internet connectivity by itself isn't a good test because if they're using any DNS at all then they would be able to access websites -- just not your internal ones via host. Do this on one of your LInux clients:

    Run a terminal and then run these commands:

    nslookup
    server your.pfsense.lan.ipaddress
    pfsense.smart.az

    Does it resolve properly then when you explicitly tell it to use your pfSense DNS?



  • Output from Linux machine:
    elvin@elvin-HP-EliteBook-Revolve-810-G2:~$ nslookup

    192.168.2.100
    ** server can't find 100.2.168.192.in-addr.arpa: NXDOMAIN
    192.168.2.1
    ** server can't find 1.2.168.192.in-addr.arpa: NXDOMAIN
    192.168.2.211
    ** server can't find 211.2.168.192.in-addr.arpa: NXDOMAIN

    Output from Windows machine
    Microsoft Windows [Version 10.0.16299.371]
    (c) 2017 Microsoft Corporation. All rights reserved.

    C:\Users\Elvin>nslookup
    Default Server: pfsense.smart.az
    Address: 192.168.4.1

    192.168.2.100
    Server: pfsense.smart.az
    Address: 192.168.4.1

    Name: vcenter.smart.local
    Address: 192.168.2.100

    192.168.2.211
    Server: pfsense.smart.az
    Address: 192.168.4.1

    Name: cpanel.smart.az
    Address: 192.168.2.211



  • Why are you doing forward lookups on Windows but reverse lookups on Linux?? The output should be similar under Windows or Linux.



  • Acutally, it doesn't matter if you enter fqdn or ip address in nslookup, it should resolve both.



  • YOU need to specify to use pfSense as your DNS with the nslookup command otherwise it uses the client's default DNS config:

    server 192.168.4.1

    THEN try to lookup vcenter.smart.az:

    nslookup
    server 192.168.4.1
    vcenter.smart.az

    What does it come back with?

    What is the contents of your Linux client's /etc/resolv.conf file?

    Acutally, it doesn't matter if you enter fqdn or ip address in nslookup, it should resolve both.

    You are trying to resolve hostnames to IP addresses. That was your stated problem. Doing a reverse lookup doesn't help you with that.