I’m having a strange issue, when I poll from an OSX based machine I have zero failures, when I do the same from a debian linux based server i have polling failures (about 97% success)
Any one who hs been seeing the same ?
I’m getting closer by eliminating devices, it starts to look like a bug in my switches which only affects ipv6 …
Interesting… Please let us know when you learn more details.
Did you check the DNS reponses?
I notioced before that not al routers handle IPv6 DNS-caching properly.
I opened a ticked with AVM a multiple times before, and they can’t reproduce it, where I can all the time.
I stopped opening tickets, as it’s of no use.
What happens for me is this, Fritz-DNS cache:
bas@workstation:~$ nslookup ntp.heppen.be 192.168.1.1
Server: 192.168.1.1
Address: 192.168.1.1#53
Non-authoritative answer:
Name: ntp.heppen.be
Address: 89.207.129.63
Name: ntp.heppen.be
Address: 212.187.8.48
Name: ntp.heppen.be
Address: 77.109.90.72
Name: ntp.heppen.be
Address: 5.135.125.103
Name: ntp.heppen.be
Address: 5.196.189.119
But the real response should be:
bas@workstation:~$ nslookup ntp.heppen.be 1.1.1.1
Server: 1.1.1.1
Address: 1.1.1.1#53
Non-authoritative answer:
Name: ntp.heppen.be
Address: 5.135.125.103
Name: ntp.heppen.be
Address: 212.187.8.48
Name: ntp.heppen.be
Address: 89.207.129.63
Name: ntp.heppen.be
Address: 5.196.189.119
Name: ntp.heppen.be
Address: 77.109.90.72
Name: ntp.heppen.be
Address: 2a02:578:440e:0:aaa1:59ff:fe3d:5b53
Name: ntp.heppen.be
Address: 2a02:578:440e:0:5f05:fa04:1720:d90f
Name: ntp.heppen.be
Address: 2001:41d0:203:654d::8f37:5630
Name: ntp.heppen.be
Address: 2a00:7b80:477:21::9dcb:d174
Because of this problem I do not use the routers-DNS anymore for my internal network, it can’t be trusted.
Maybe you have the same problem, just a suggestion.
The problem is not with the gateway, but with nslookup. Try it again using dig or host.
No it’s a problem of the router.
nslookup works fine.
When I nslookup at other servers but NOT my own location, it resolves fine.
It also does when asking 1.1.1.1
Running an IPv6 servers locally but resolve the DNS, it will go nuts and doesn’t resolve properly.
This is a router problem.
Did you even try? Because the output from nslookup for me looks just like yours, but i use an Ubiquiti router. However, the output by either dig or host includes both the v4 and the v6 addresses of your hosts.
1 Like
Not using fritz stuff 
after doing some test I replaced my core switch and anything not passing thru the old switches is just working fine now. Let’s seen if it remains stable …
1 Like
Bug or feature? I still suspect the ‘DNS rebinding’-protection of your Fritz!Box might be causing this.
But we already discussed that extensively here. Did you ever tried the rebind-test that I put up especially for you (as in: your specific situation) in that article? I can’t remember… Bit it is still there, should you want to give it a go.
1 Like
Yep exactly as you described, it didn’t work. I gave up on the problem and use an external DNS on all my machines, now they happily resolve IPv6.
Perhaps that is useful input for the ticket you opened with AVM? If I understand you correctly, trying to exclude (internal) hosts from the DNS rebinding protection does not seem to work.
Anyway, glad to read you found a work around.
1 Like