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

    DNS randomly stops working

    Scheduled Pinned Locked Moved DHCP and DNS
    39 Posts 14 Posters 10.2k 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.
    • S
      SashLi
      last edited by

      Same issue here but on 2.5.1. The DNS Server stopped working. The strange thing is that netstat is showing that port 23 is bounded and the gui showing that the service is running but there is no way to get a DNS resolve via the localhost server ( already checked bound interfaces ). Have a box with the same configuration on 2.5.0 and that is working correctly. It is also working if I'm using a external DNS server only with setting to ignore the local

      GertjanG 1 Reply Last reply Reply Quote 0
      • GertjanG
        Gertjan @SashLi
        last edited by

        @sashli said in DNS randomly stops working:

        The strange thing is that netstat is showing that port 23 is bounded

        That's a telnet server. Not DNS related.

        @sashli said in DNS randomly stops working:

        and the gui showing that the service is running

        Do this extra test:

        ps ax | grep `cat /var/run/unbound.pid`
        

        If it shows :

        xxxxxx-  Ss      5:23.38 /usr/local/sbin/unbound -c /var/unbound/unbound.conf
        

        You will know for sure that unbound is there.

        sockstat | grep 'unbound'
        

        or

        sockstat | grep '53'
        

        shows you on which interfaces it lists.
        "netstat" is more a linux command. It's "sockstat" for FreeBSD.

        For me, it listens to all interfaces (no exceptions) :

        unbound unbound 6660 3 udp6 *:53 :
        unbound unbound 6660 4 tcp6 *:53 :
        unbound unbound 6660 5 udp4 *:53 :
        unbound unbound 6660 6 tcp4 *:53 :
        unbound unbound 6660 7 tcp4 127.0.0.1:953 :

        and this for TCP and UDP, IPv4 and IPv6.
        This includes localhost == the old 127.0.0.1 or thew ::1.

        The '953' is the special control access, which is only IPv4 - localhost.

        [2.5.0-RELEASE][admin@pfsense.mylocal.net]/var/run: dig @::1 pfsense.mylocal.net. +short
        192.168.1.1
        

        This means that unbound is up, running, and answering.

        Also : 2.5.1 has some unbound related updates/upgrades.
        I installed and tested it @home since yesterday. It's as good as 2.5.0 (and in theory better ^^)

        @sashli said in DNS randomly stops working:

        Have a box with the same configuration on 2.5.0 and that is working correctly.

        This means : compare the two (only the settings you changed from default) and you'll have your answer.

        No "help me" PM's please. Use the forum, the community will thank you.
        Edit : and where are the logs ??

        S 1 Reply Last reply Reply Quote 0
        • V
          vjizzle
          last edited by

          Unbound on 2.5 CE crashed regularly for me also. For the brief period that I was on 2.5.1 CE unbound did not crash. I did find that when I upgrade unbound pfSense 2.5 it is not crashing anymore. You can do this from the Command Prompt or shell access.

          The command: pkg upgrade -fy unbound

          Installed packages to be UPGRADED:
          	unbound: 1.13.0_2 -> 1.13.1 [pfSense]
          

          Make sure to have backups before you do this :). I did find that this makes unbound stable on pfSense 2.5 CE for me but YMMV.

          1 Reply Last reply Reply Quote 0
          • S
            SashLi @Gertjan
            last edited by

            @gertjan same result. host is showing that unbound is up and working but not resolving.

            ps ax | grep `cat /var/run/unbound.pid`
            
            
            12809  -  Is      0:00.02 /usr/local/sbin/unbound -c /var/unbound/unbound.conf
            

            sockstat report running service

            unbound  unbound    36677 4  udp6   *:53                  *:*
            unbound  unbound    36677 5  tcp6   *:53                  *:*
            unbound  unbound    36677 6  udp4   *:53                  *:*
            unbound  unbound    36677 7  tcp4   *:53                  *:*
            unbound  unbound    36677 8  tcp4   127.0.0.1:953         *:*
            

            Doing a dig on local now lead to

            dig @::1 pfsense.org +short
            net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
            208.123.73.69
            

            the stange thing is when trying to do this against the IPv4 localhost 127.0.0.1

            dig @127.0.0.1 pfsense.org +short
            net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
            
            ; <<>> DiG 9.16.12 <<>> @127.0.0.1 pfsense.org +short
            ; (1 server found)
            ;; global options: +cmd
            ;; connection timed out; no servers could be reached
            

            Also trying the GUI DNS Test fail with no response. I added the ::1 to test if it is a problem resolving against 127.0.0.1 only

            DNS issue.png

            J GertjanG 2 Replies Last reply Reply Quote 0
            • J
              juniper @SashLi
              last edited by

              @sashli same problem here:

              after upgrading pfsense from 2.5.0 to 2.5.1 unboud stop responding on 127.0.0.1:

              [2.5.1-RELEASE][admin@ids.********.**]/etc/defaults: dig @127.0.0.1
              net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
              
              
              [2.5.1-RELEASE][admin@ids.*********.**]/etc/defaults: ping 127.0.0.1
              PING 127.0.0.1 (127.0.0.1): 56 data bytes
              ping: sendto: Can't assign requested address
              ping: sendto: Can't assign requested address
              ping: sendto: Can't assign requested address
              ping: sendto: Can't assign requested address
              
              

              unbound service starts:

              [2.5.1-RELEASE][admin@ids.********.**]/etc/defaults: netstat -ln
              Active Internet connections
              Proto Recv-Q Send-Q Local Address                                 Foreign Address                               (state)    
              tcp4       0      0 10.10.200.2.443                               10.10.15.3.56532                              ESTABLISHED
              tcp4       0     44 10.10.200.2.22                                10.10.15.3.37490                              ESTABLISHED
              tcp4       0      0 10.10.200.2.22                                10.10.15.3.37488                              ESTABLISHED
              udp6       0      0 ::1.53                                        *.*                                           
              udp4       0      0 127.0.0.1.53                                  *.*                                           
              
              

              On pfsense firewall we have snort and pfblockerNG, nothing is changed from 2.5.0, we have only upgraded pfsense.

              Some suggestion?

              1 Reply Last reply Reply Quote 1
              • GertjanG
                Gertjan @SashLi
                last edited by

                @sashli said in DNS randomly stops working:

                dig @127.0.0.1 pfsense.org +short

                Let's add some details.
                Lot's of details.

                dig @127.0.0.1 pfsense.org +trace
                

                But the real issue is here :

                net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
                

                'dig' is not family of, or related to 'unbound'.
                dig comes from the bind FreeBSD package 'bind-tools'.

                "net.c" is one of the main source code files, and it can not "use the IP you gave" ... it can not use "127.0.0.1" so it can contact unbound over 127.0.0.1 port 53 UDP.

                When I stop unbound - so no one is listing on 127.0.0.1 port 53, and execute a
                dig @127.0.0.1 pfsense.org +trace
                it comes back after several seconds with a logical "connection timed out; no servers could be reached"

                You have interface problems ..... and not 'unbound' problems. unbound is yet another victim of the real issue.

                No "help me" PM's please. Use the forum, the community will thank you.
                Edit : and where are the logs ??

                J S 2 Replies Last reply Reply Quote 1
                • J
                  juniper @Gertjan
                  last edited by

                  @gertjan yes problem is related to interfaces...

                  if i try to ping 127.0.0.1 i've the same error...

                  Someone opened a bug for that?

                  1 Reply Last reply Reply Quote 1
                  • S
                    SashLi @Gertjan
                    last edited by

                    @gertjan thanks for your feedback but it looks really like a problem with the localhost 127.0.0.1 interface. I just reinstalled the ntopng and this has also problems starting and running services. Issue leading in the same direction here "Could not connect to Redis at 127.0.0.1:6379: Can't assign requested address'".

                    The question is: why is the interface on the localhost not reachable by the system itself ? Any idea ?

                    J 1 Reply Last reply Reply Quote 0
                    • J
                      juniper @SashLi
                      last edited by

                      @sashli try to ping other interfaces from pfsense itself...

                      i think is jail related or something similar...

                      S 1 Reply Last reply Reply Quote 0
                      • S
                        SashLi @juniper
                        last edited by

                        @juniper just found this ticket in redmine, not sure if this can be an issue created by this gatewax problem

                        IPv4 link-local (169.254.x.x) gateway does not function

                        J GertjanG 3 Replies Last reply Reply Quote 0
                        • J
                          juniper @SashLi
                          last edited by

                          @sashli i don't know...

                          I can add an information, my pfsense installation is on proxmox ve virtual machine.

                          1 Reply Last reply Reply Quote 0
                          • GertjanG
                            Gertjan @SashLi
                            last edited by Gertjan

                            @sashli said in DNS randomly stops working:

                            @juniper just found this ticket in redmine, not sure if this can be an issue created by this gatewax problem

                            IPv4 link-local (169.254.x.x) gateway does not function

                            That's a special case, using IP's like 169.254.0.0/16.
                            There is a small patch for this - jimp posted one yesterday.

                            I've updated my pfSense at home (Hyper-V = VM) based : it's just perfect.
                            I've just updated my work pfSense, they update went just fine. Again perfect.

                            127.0.0.1 isn't even an external driver related, as it is part of the build in 'kernel' IP stack facilities.

                            Use another VM host - if you have a Windows 10 Pro somewhere, you could make one right away, or install pfSense bare bone and you see that their is - can not be - localhost issues, as it will break everything.

                            Just to be sure : your issue exists after you reset to default - and you only changed the password (!! did NOT import your settings !!) ?

                            No "help me" PM's please. Use the forum, the community will thank you.
                            Edit : and where are the logs ??

                            1 Reply Last reply Reply Quote 0
                            • J
                              juniper @SashLi
                              last edited by

                              @sashli

                              Problem appear if i insert 127.0.0.1 on GENERAL SETUP---DNS Server Settings

                              I use to have there 127.0.0.1 if pfsense is a dns resolver.

                              If i config with 127.0.0.1 GENERAL SETUP---DNS Server Settings as a default pfsense dns server there is the problem with interface lo0.

                              Cool_CoronaC GertjanG 2 Replies Last reply Reply Quote 0
                              • Cool_CoronaC
                                Cool_Corona @juniper
                                last edited by

                                @juniper Then you create a loopback??

                                If nothing is in General setup then it uses localhost.

                                J 1 Reply Last reply Reply Quote 0
                                • J
                                  juniper @Cool_Corona
                                  last edited by

                                  @cool_corona no i use 127.0.0.1 as dns resolver for pfsense.

                                  Cool_CoronaC 1 Reply Last reply Reply Quote 0
                                  • Cool_CoronaC
                                    Cool_Corona @juniper
                                    last edited by

                                    @juniper Leave it blank and

                                    c42bdb5c-69d0-4613-aaa1-c3ee3c07a586-billede.png

                                    And reboot

                                    J 1 Reply Last reply Reply Quote 0
                                    • J
                                      juniper @Cool_Corona
                                      last edited by

                                      @cool_corona yes it works!

                                      Problem appear if i use 127.0.0.1 in general setup.

                                      If i set an external dns and set dns resolution behavior as you suggest all working fine.

                                      Thank you.

                                      S 1 Reply Last reply Reply Quote 0
                                      • S
                                        SashLi @juniper
                                        last edited by

                                        @juniper exactly its a problem when 127.0.0.1 is listed in the general setup of the DNS server list.

                                        1 Reply Last reply Reply Quote 0
                                        • GertjanG
                                          Gertjan @juniper
                                          last edited by Gertjan

                                          @juniper

                                          Why do you want to add 127.0.0.1 here :

                                          3197d809-b8b8-429c-a2ea-0c84b2205d2d-image.png

                                          ?

                                          As you can see, I have nothing.
                                          Because that's default : nothing.

                                          Still, the magic is happening :

                                          68290cff-a748-408d-982a-c8786d8d29b0-image.png

                                          I hope (didn't test) that pfSense is intelligent enough that, when 127.0.0.1 is added here :
                                          5b501b55-8d28-4178-bd89-5705249afe46-image.png

                                          It will ignore that 'request' as 127.0.0.1 is already there.
                                          Here it is :
                                          /etc/resolv.conf .......

                                          nameserver 127.0.0.1
                                          search your-domain.tld
                                          

                                          Ok, I broke my won rules ™ © and added some DNS settings myself.

                                          9b5470ef-d9e7-47a1-8158-ea67587c4040-image.png

                                          5878155b-aae4-4e95-b20c-414957138a27-image.png

                                          but /etc/resolv.conf didn't change.
                                          I'm missing something ....

                                          But pfSense (unbound) works.

                                          edit : this is a no go :

                                          [2.5.1-RELEASE][admin@pfsense.my-domain.tld]/root: dig @127.0.0.1 google.com
                                          net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
                                          net.c:536: probing sendmsg() with IPV6_TCLASS=b8 failed: No route to host

                                          Ok. Great.
                                          Who calls Houston ?

                                          Solution : remove ::1 and 127.0.0.1 from the General settings as it was
                                          Useless (before)
                                          Break things (today).

                                          So, please : don't do that ;)

                                          edit : even why I removed ::1 and 127.0.0.1 I had could not use "127.0.0.1" any more.

                                          It was :

                                          net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
                                          

                                          all the time now.

                                          Si, guys,I don't quiet understand what I'm seeing, but I see what you see.

                                          Unbound wasn't listening to 127.0.0.1 any more - I restarted unbound : didn't help. I had to restart "127.0.0.1" - if possible.
                                          I had to reboot pfSense - as this is a way to 'restart' the kernel.

                                          No "help me" PM's please. Use the forum, the community will thank you.
                                          Edit : and where are the logs ??

                                          E 1 Reply Last reply Reply Quote 1
                                          • E
                                            e-1-1 @Gertjan
                                            last edited by

                                            @gertjan Personally had 127.0.0.1 from before that "DNS Resolution Behavior" section existed, a couple of years at least.
                                            If memory serves right 🤔
                                            Guess that's because we wanted to ensure the system used its own resolver, and that only.

                                            Was stunned when all DNS resolution stopped after upgrading to 2.5.1. Not even pkg worked :)
                                            But some dig(ging) lead to the entry removal, then restoration of DNS service.

                                            No bug listed as of now that I can find, but @jimp could we have this case covered in the pfsense-upgrade script that gets updated when pressing "13" in the CLI? It would eliminate the 127.0.0.1 entry, as workaround for now in place of debugging the lovely

                                            net.c:536: probing sendmsg() with IP_TOS=b8 failed: Can't assign requested address
                                            

                                            bork message.

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