Solved - Re: It is the firewall rule? - Re: Ubuntu 24.04 unbound install problems -- resolv.conf

Robert Moskowitz rgm at htt-consult.com
Thu Jun 12 14:11:22 UTC 2025


I, of all people, can't do my CIDR numbering.

ufw allow in from 192.168.0.0/16 to any port 53

Sigh.

I mean I was in the room when Tony Li and Jacov Rekhter were going at it 
on however the mask rules would work....

And I took notes!  I mean they are probably still around somewhere on my 
current notebook.

Grumble.

Fun couple of guys!  Even when they strongly disagreed on something.

On 6/12/25 10:00 AM, Robert Moskowitz via ubuntu-users wrote:
> I disabled ufw:
>
> ufw disable
>
> And now dig works for a local client.
>
> I have tried different set of firewall rules:
>
> ufw allow in from 23.123.122.144/28 to any port 53
> ufw allow in from 192.168.0.0/20 to any port 53
>
> and
>
> ufw allow in from 23.123.122.144/28 to any port 53 proto udp
> ufw allow in from 192.168.0.0/20 to any port 53 proto udp
> ufw allow in from 23.123.122.144/28 to any port 53 proto tcp
> ufw allow in from 192.168.0.0/20 to any port 53 proto tcp
>
> neither works.  I get a timeout on dig with firewall enabled.
>
>
> On 6/12/25 8:47 AM, Robert Moskowitz via ubuntu-users wrote:
>> First, I am not skilled with Ubuntu.  This is only my second Ubuntu 
>> server, and my first was pretty much turn-key for Mail-in-a-Box with 
>> Ubuntu 22.  My decades of experience is with CentOS/Fedora.  Thus at 
>> times it is easy (general Linux), and other times I am lost as to 
>> where things are.
>>
>> So:
>>
>> My unbound is on a public address on my home business network. You 
>> should ping it at onlo.htt-consult.com.  But firewall rules will 
>> block you from accessing DNS.  Also that is not my SSH port below...
>>
>> My plan is for all internal systems to point to it for DNS resolution.
>>
>> in unbound.conf, I have allowed access for my local systems:
>>
>>       interface: 0.0.0.0
>>
>>       access-control: 23.123.122.144/28 allow
>>       access-control: 192.168.128.0/17 allow
>>       access-control: 192.168.64.0/21 allow
>>       access-control: 192.168.96.0/21 allow
>>       access-control: 127.0.0.1/24 allow
>>
>> (BTW, I do play games with local RFC1918 IPv4 addrs.  Afterall, I am 
>> the lead author of that RFC.  I also worked in the CIDR workgroup at 
>> the time.)
>>
>> Then I opened up firewall for DNS:
>>
>> ufw allow in from 23.123.122.144/28 to any port 53
>> ufw allow in from 192.168.0.0/24 to any port 53
>>
>> I can't find out if this makes the rules permanent, but at the time 
>> of testing, they were in force.
>>
>> But I can't dig from my notebook:
>>
>> dig @onlo.htt-consult.com <http://onlo.htt-consult.com> A 
>> medon.htt-consult.com <http://medon.htt-consult.com>
>> ;; communications error to 23.123.122.146#53: timed out
>> ;; communications error to 23.123.122.146#53: timed out
>> ;; communications error to 23.123.122.146#53: timed out
>>
>> ; <<>> DiG 9.18.33 <<>> @onlo.htt-consult.com 
>> <http://onlo.htt-consult.com> A medon.htt-consult.com 
>> <http://medon.htt-consult.com>
>> ; (1 server found)
>> ;; global options: +cmd
>> ;; no servers could be reached
>>
>> And the unbound server's resolv.conf is not working?  local nslookup 
>> fails.
>>
>> So basically how do I trouble-shoot this?
>>
>> On 6/11/25 11:48 PM, Jared Norris wrote:
>>> Hi Robert,
>>>
>>> I use Unbound at home and might have a slightly different take. I 
>>> point my local router at an Unbound instance (running on a Raspberry 
>>> Pi) as the DNS service then set up Unbound using unbound.conf
>>>
>>> That way the whole network is using Unbound, not just my local PC. 
>>> That also means there is no config on any computer, just set it up 
>>> once on the router.
>>>
>>> I use it alongside Pihole and find it works well, they have 
>>> documentation to help with the set up and they mention a 
>>> resolve.conf issue with a workaround that may also help even if you 
>>> want to still run it locally - 
>>> https://docs.pi-hole.net/guides/dns/unbound/
>>>
>>> Regards,
>>>
>>> Jared Norris
>>>
>>> On Thu, 12 Jun 2025 at 08:29, Robert Moskowitz via ubuntu-users 
>>> <ubuntu-users at lists.ubuntu.com> wrote:
>>>
>>>     I have been following the cookbook at:
>>>
>>>     https://www.linuxbabe.com/ubuntu/set-up-unbound-dns-resolver-on-ubuntu-20-04-server
>>>
>>>     which is really for Ubuntu 22.
>>>
>>>     I got through his getting unbounded running.
>>>
>>>     systemctl status unbound
>>>     ● unbound.service - Unbound DNS server
>>>           Loaded: loaded (/usr/lib/systemd/system/unbound.service;
>>>     enabled;
>>>     preset: >
>>>           Active: active (running) since Wed 2025-06-11 18:02:18
>>>     EDT; 26s ago
>>>             Docs: man:unbound(8)
>>>          Process: 5494 ExecStartPre=/usr/libexec/unbound-helper
>>>     chroot_setup
>>>     (code=e>
>>>          Process: 5496 ExecStartPre=/usr/libexec/unbound-helper
>>>     root_trust_anchor_up>
>>>         Main PID: 5499 (unbound)
>>>            Tasks: 1 (limit: 928)
>>>           Memory: 8.2M (peak: 8.6M)
>>>              CPU: 89ms
>>>           CGroup: /system.slice/unbound.service
>>>                   └─5499 /usr/sbin/unbound -d -p
>>>
>>>     netstat -tulpn
>>>     Active Internet connections (only servers)
>>>     Proto Recv-Q Send-Q Local Address           Foreign Address State
>>>     PID/Program name
>>>     tcp        0      0 0.0.0.0:53 <http://0.0.0.0:53> 0.0.0.0:* LISTEN
>>>     5499/unbound
>>>     tcp6       0      0 :::7456                  :::* LISTEN      1/init
>>>     udp        0      0 0.0.0.0:53 <http://0.0.0.0:53> 0.0.0.0:*
>>>     5499/unbound
>>>
>>>
>>>     And setting firewall rules:
>>>
>>>     Status: active
>>>
>>>     To                         Action      From
>>>     --                         ------      ----
>>>     7456                        ALLOW       Anywhere
>>>     53                         ALLOW 23.123.122.144/28
>>>     <http://23.123.122.144/28>
>>>     53                         ALLOW 192.168.0.0/24
>>>     <http://192.168.0.0/24>
>>>     7456 (v6)                   ALLOW       Anywhere (v6)
>>>
>>>     Now I am up to resolv.conf.
>>>
>>>     I thought to be smart and set nameserver 127.0.0.1in my netplan.
>>>     Easy,
>>>     as I am on a fixed plan
>>>
>>>     But
>>>
>>>     cat /etc/resolv.conf
>>>     # This is /run/systemd/resolve/stub-resolv.conf managed by
>>>     man:systemd-resolved(8).
>>>     # Do not edit.
>>>     #
>>>     # This file might be symlinked as /etc/resolv.conf. If you're
>>>     looking at
>>>     # /etc/resolv.conf and seeing this text, you have followed the
>>>     symlink.
>>>     #
>>>     # This is a dynamic resolv.conf file for connecting local
>>>     clients to the
>>>     # internal DNS stub resolver of systemd-resolved. This file
>>>     lists all
>>>     # configured search domains.
>>>     #
>>>     # Run "resolvectl status" to see details about the uplink DNS
>>>     servers
>>>     # currently in use.
>>>     #
>>>     # Third party programs should typically not access this file
>>>     directly,
>>>     but only
>>>     # through the symlink at /etc/resolv.conf. To manage
>>>     man:resolv.conf(5) in a
>>>     # different way, replace this symlink by a static file or a
>>>     different
>>>     symlink.
>>>     #
>>>     # See man:systemd-resolved.service(8) for details about the
>>>     supported
>>>     modes of
>>>     # operation for /etc/resolv.conf.
>>>
>>>     nameserver 127.0.0.53
>>>     options edns0 trust-ad
>>>     search htt-consult.com <http://htt-consult.com>
>>>
>>>     not 127.0.0.1
>>>
>>>     So then I set my netplan back to the regular nameservers and
>>>     tried to
>>>     follow his instructions to
>>>
>>>     systemctl restart unbound-resolvconf.service
>>>
>>>     But this fails  I am suppose to
>>>
>>>     apt install openresolv
>>>
>>>     But this has been pulled as of Ubuntu 23.
>>>
>>>     So how do I finish up this unbound setup?
>>>
>>>     I tried nslookup on my server.  It times out.  From my "allowed"
>>>     local
>>>     addresses I tried:
>>>
>>>     dig @onlo.htt-consult.com <http://onlo.htt-consult.com> A
>>>     medon.htt-consult.com <http://medon.htt-consult.com>
>>>     ;; communications error to 23.123.122.146#53: timed out
>>>     ;; communications error to 23.123.122.146#53: timed out
>>>     ;; communications error to 23.123.122.146#53: timed out
>>>
>>>     ; <<>> DiG 9.18.33 <<>> @onlo.htt-consult.com
>>>     <http://onlo.htt-consult.com> A medon.htt-consult.com
>>>     <http://medon.htt-consult.com>
>>>     ; (1 server found)
>>>     ;; global options: +cmd
>>>     ;; no servers could be reached
>>>
>>>     thank you for your help.
>>>
>>>
>>>
>>>     -- 
>>>     ubuntu-users mailing list
>>>     ubuntu-users at lists.ubuntu.com
>>>     Modify settings or unsubscribe at:
>>>     https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
>>>
>>>
>>
>>
>
>
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