# Trying to understand DNS settings and a lot of problems

**URL:** <https://discourse.mailinabox.email/t/trying-to-understand-dns-settings-and-a-lot-of-problems/10145>\
**Category:** Help with Setup/Upgrade\
**Created:** [February 17, 2023, 12:56pm UTC](https://discourse.mailinabox.email/t/trying-to-understand-dns-settings-and-a-lot-of-problems/10145 "2023-02-17T12:56:19Z")\
**Posts on this page:** 1\
**Showing post:** 21

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**Author:** ![ewsg576](https://discourse.mailinabox.email/letter_avatar_proxy/v4/letter/e/65b543/32.png) [@ewsg576](https://discourse.mailinabox.email/u/ewsg576)\
**Post date:** [February 27, 2023, 1:18pm UTC](https://discourse.mailinabox.email/t/trying-to-understand-dns-settings-and-a-lot-of-problems/10145/21 "2023-02-27T13:18:31Z")

</div>

Hi again,

Well I mentioned in [other thread](https://discourse.mailinabox.email/t/error-something-went-wrong-sorry-when-accessing-external-dns/10162/4) some errors I get.

They are below, maybe they can help to identify the cause of the problem:

```auto
Exception on /dns/dump [GET]
                                                 Traceback (most recent call last):
                                                 File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask>/app.py", line 252>
                                                 response = self.full_dispatch_request()
                                                 File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 182>
                                                     rv = self.handle_user_exception(e)

```

And:

```auto
xception on /dns/dump [GET]
                                                  Traceback (most recent call last):
                                                    File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 2528, in wsgi_app
                                                      response = self.full_dispatch_request()
                                                    File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 1825, in full_dispatch_request
                                                      rv = self.handle_user_exception(e)
                                                    File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 1823, in full_dispatch_request
                                                      rv = self.dispatch_request()
                                                    File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 1799, in dispatch_request
                                                      return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
                                                    File "/home/ed/mailinabox/management/daemon.py", line 75, in newview
                                                      return viewfunc(*args, **kwargs)
                                                    File "/home/ed/mailinabox/management/daemon.py", line 397, in dns_get_dump
                                                      return json_response(build_recommended_dns(env))
                                                    File "/home/ed/mailinabox/management/dns_update.py", line 1084, in build_recommended_dns
                                                      for (domain, zonefile, records) in build_zones(env):
                                                    File "/home/ed/mailinabox/management/dns_update.py", line 175, in build_zones
                                                      records = build_zone(domain, domains, additional_records, env)
                                                    File "/home/ed/mailinabox/management/dns_update.py", line 224, in build_zone
                                                      subzone = build_zone(subdomain, domain_properties, additional_records, env, is_zone=False)
                                                    File "/home/ed/mailinabox/management/dns_update.py", line 215, in build_zone
                                                      for value in build_sshfp_records():
                                                    File "/home/ed/mailinabox/management/dns_update.py", line 468, in build_sshfp_records
                                                      keys = shell("check_output", ["ssh-keyscan", "-t", "rsa,dsa,ecdsa,ed25519", "-p", str(port), "localhost"])
                                                    File "/home/ed/mailinabox/management/utils.py", line 126, in shell
                                                      ret = getattr(subprocess, method)(cmd_args, **kwargs)
                                                    File "/usr/lib/python3.10/subprocess.py", line 420, in check_output
                                                      return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
                                                    File "/usr/lib/python3.10/subprocess.py", line 524, in run
                                                      raise CalledProcessError(retcode, process.args,
                                                  subprocess.CalledProcessError: Command '['ssh-keyscan', '-t', 'rsa,dsa,ecdsa,ed25519', '-p', '22', 'localhost']' returned non-zero exit status 1.

```

Thanks once again for your help.

P.S.: I also found the below lines in `/var/log/syslog`. Just after I tried to access the External DNS page (obtaining the 500 error):

```auto
Feb 27 10:29:00 box Exception on /dns/dump [GET]#012Traceback (most recent call last):#012 File "/usr/local/lib/mailinabox/env/lib/python3.10/site-packages/flask/app.py", line 2528, in wsgi_app#012 response = self.full_dispatch_requ>
Feb 27 10:29:11 box kernel: [265238.333680] [UFW BLOCK] IN=eth0 OUT= MAC=f2:3c:93:e6:f2:bb:fe:ff:ff:ff:ff:ff:08:00 SRC=95.214.54.4 DST=SERVER_IP LEN=40 TOS=0x08 PREC=0x20 TTL=240 ID=5381 PROTO=TCP SPT=59747 DPT=30213 WINDOW=1024 R>

```

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