Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    pfsense block sites random

    Scheduled Pinned Locked Moved General pfSense Questions
    14 Posts 4 Posters 1.4k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • L
      lp.14
      last edited by

      Hi all,

      I saw a lot of topic about this but I didn't find the answer, so i ask you.
      pfsense randomly block sites ( eg parallels.com ) why ? how can i solve this ?

      i tried a lot of tricks like
      Disables the PF scrubbing option which can sometimes interfere with NFS traffic.
      and
      Disable hardware checksum offload

      but it didn't work

      any solution please ?

      thanks
      best regards

      R 1 Reply Last reply Reply Quote 0
      • R
        rcoleman-netgate Netgate @lp.14
        last edited by

        @lp-14 what packages are you running? Is the pfSense doing your DNS? Do you have other DNS-assisting programs installed like pfBlockerNG?

        Ryan
        Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
        Requesting firmware for your Netgate device? https://go.netgate.com
        Switching: Mikrotik, Netgear, Extreme
        Wireless: Aruba, Ubiquiti

        1 Reply Last reply Reply Quote 0
        • L
          lp.14
          last edited by

          thanks for the reply

          no i don't have packages added .. only nmap or acme or openvpn
          my dns setup in general setting point to google dns or isp dns and in dhcp setting no specify dns. no dns resolver or forwarder configured

          thanks
          best regards

          R 1 Reply Last reply Reply Quote 0
          • R
            rcoleman-netgate Netgate @lp.14
            last edited by

            @lp-14 If you're bypassing the internal DNS altogether then your pf is likely not blocking anything but your DNS is not resolving and that's upstream.

            Check the domain that fails to resolve next against the Root server list on the pf -- Diagnostics->DNS Lookup

            Ryan
            Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
            Requesting firmware for your Netgate device? https://go.netgate.com
            Switching: Mikrotik, Netgear, Extreme
            Wireless: Aruba, Ubiquiti

            1 Reply Last reply Reply Quote 0
            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              Check the causes here: https://docs.netgate.com/pfsense/en/latest/troubleshooting/website-access-issues.html

              Particularly the MTU on the WAN.

              1 Reply Last reply Reply Quote 0
              • L
                lp.14
                last edited by

                i just did test with:

                ping -f -l 1472 www.dslreports.com

                from a windows vm in paralells app.. and i get the exact value of 1472 like mtu, i set up it in pfsense but nothing changed

                sites like parallels.com is still unaccesable but from diagnostinc dns lookup i can get it easily

                what's wrong ?
                Please suggest me something
                really thanks
                best regards

                M 1 Reply Last reply Reply Quote 0
                • M
                  michmoor LAYER 8 Rebel Alliance @lp.14
                  last edited by

                  @lp-14 You are using something else other than pfSense for DNS, correct?
                  What happens when you configure your client to use pfSense for DNS?
                  Can you try a different browser on your client?

                  Firewall: NetGate,Palo Alto-VM,Juniper SRX
                  Routing: Juniper, Arista, Cisco
                  Switching: Juniper, Arista, Cisco
                  Wireless: Unifi, Aruba IAP
                  JNCIP,CCNP Enterprise

                  1 Reply Last reply Reply Quote 0
                  • L
                    lp.14
                    last edited by

                    ok solved, in services dhcp server for each network i specified manually what dns to use. I expected it used automatically the firewall

                    stephenw10S 1 Reply Last reply Reply Quote 0
                    • stephenw10S
                      stephenw10 Netgate Administrator @lp.14
                      last edited by

                      @lp-14 said in pfsense block sites random:

                      I expected it used automatically the firewall

                      It does. If you don't set a DNS server in the DHCP server it will pass the interface address or clients to use.

                      1 Reply Last reply Reply Quote 0
                      • L
                        lp.14
                        last edited by

                        let's say .. it should, cause in my case i have:
                        the firewall with dns in general setting
                        8.8.8.8
                        and 192.168.1.200
                        and block sites...

                        i add in dhcp server

                        8.8.8.8
                        192.168.1.200
                        and the ip of the firewall it self

                        and don't block sites

                        1 Reply Last reply Reply Quote 0
                        • stephenw10S
                          stephenw10 Netgate Administrator
                          last edited by

                          If you pass 3 DNS servers to the clients via DHCP like that it's entirely up to the client which one it uses. So potentially i could fail to resolve something depending on which one it uses.

                          The DNS settings in System > General Setup apply only to the firewall itself and not to clients behind it. With no DNS values in the DHCP server settings it will pass the pfSense interface IP which mean clients use Unbound in pfSense. That's the default setup.

                          1 Reply Last reply Reply Quote 0
                          • L
                            lp.14
                            last edited by

                            thanks for the reply

                            starting situation was:

                            dns in general setting of the firewall and no dns in dhcp server
                            sometimes failed to bring me to the sites

                            was normal ?

                            thanks

                            1 Reply Last reply Reply Quote 0
                            • stephenw10S
                              stephenw10 Netgate Administrator
                              last edited by

                              No, not if everything else was default. The DNS resolver is enabled with it's default config for example.

                              It resolves the IPs directly and passes those to clients. It also caches IPs so you wouldn't expect to see failures on the clients in quick succession.

                              1 Reply Last reply Reply Quote 1
                              • L
                                lp.14
                                last edited by

                                I solved setting dns in dhcp relay setting

                                thanks

                                1 Reply Last reply Reply Quote 0
                                • First post
                                  Last post
                                Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.