dns not working with wifi?

rblampain · 04-20-2018, 05:11 AM

I have a vodafone "pocketwifi R216H" WiFi linking my home machines to the Internet and a Linode remote server just provisioned with an OS and Apache2 (including ~/html/index.html). DNS is hosted by Crazydomains.

Code:

Name Server 1 ns1.linode.com 162.159.27.72,2400:cb00:2049:1::a29f:1a63
Name Server 2 ns2.linode.com 162.159.24.39,2400:cb00:2049:1::a29f:1827
Name Server 3 ns3.linode.com 162.159.25.129,2400:cb00:2049:1::a29f:1981
Name Server 4 ns4.linode.com 162.159.26.99,2400:cb00:2049:1::a29f:1b48
Name Server 5 ns5.linode.com 162.159.24.25 
Host Records ns2.nobla.org 172.104.170.97
ns1.nobla.org 172.104.170.97

I have meticulously followed Linode's instructions, I can "ssh" both root and user and copy files etc but I can only ping the Linode by ip not by hostname (Server not found.) but I know little about DNS and could be missing something.
I entered the parameters "ns?.linode.com" which prompted the addition of the ipv4 and ipv6 which seems to belong to Linode but I am only guessing that the 'auto-completion' is normal and correct rather than self-serving.
I suspect the cause is the wifi modem (dynamic ip?) or the DNS hosting is blocking resolution to IPs outside their own.
I have found two solutions that do not work for me: edit /etc/resolv.conf (without reboot) or dhclient.conf trying to add 8.8.8.8 and 8.8.4.4 (with reboot).

Perhaps it is not even possible under WiFi and I might have to test any website put on the Linode in some other way than entering the hostname in the browser.

Can someone suggest how to resolve the problem or point to suitable howto or how to find if the DNS hosting is blocking something?

Thank you for your help

smallpond · 04-20-2018, 09:40 AM

To test whether linode is resolving your domain run the commands below and look for the ANSWER section:

Code:

dig @ns1.linode.com example.com A
dig @ns1.linode.com example.com AAAA

You can also run with @8.8.8.8 to check the DNS system at large. It can take a day or so for changes to DNS to propagate through the internet.

rblampain · 04-21-2018, 10:20 AM

Thank you very much for the answer. I got the following results which I do not understand although it appears to me that my dns may not be set correctly with linode although it is not the only problem.
Can you explain what that result means?
Giving parameter "A" or "AAAA" gave the same result in both cases.

Code:

dig @ns1.linode.com nobla.org A
connection timed out; no servers could be reached

Code:

dig @8.8.8.8 nobla.org A
; <<>> DiG 9.10.3-P4-Debian <<>> @8.8.8.8 nobla.org A
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 51351
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;nobla.org.			IN	A

;; Query time: 1393 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Sat Apr 21 22:58:50 AWST 2018
;; MSG SIZE  rcvd: 38

The last change made was password on 19 on DNS hosting (Crazydomains), nameservers have not been changed for longer

scasey · 04-21-2018, 05:41 PM

dig @ns1.linode.com nobla.org A doesn't time out for me, so I'm going to say your server is not resolving ns1.linode.com properly.

What's in your /etc/resolv.conf?

However, that query does not resolve the IP for nobla.org, so, yes, the A record for that domain name is not set up correctly in the linode name servers. As those are the name servers for the domain, if they are not correct, the domain name will be unreachable.

rblampain · 04-22-2018, 03:23 AM

Code:

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver 8.8.8.8
nameserver 8.8.4.4
nameserver fe80::dac7:71ff:fe88:5650%wlp6s0 search pocket.wifivodafonemobile.api

I am only aware now that I have duplicated entries but posted it as it is and I even thought that it would have been overwiten by now (google entries would have been deleted), I added these entry lines referring to google since the file originally only had the entry for vodafone. I have not been able to find precisely how to use /etc/resolvconf.conf to get /etc/resolv.conf set properly and, given your answer, I now think I probably used an incorrect syntax.

smallpond · 04-24-2018, 02:04 PM

I don't think your domain is in the linode nameservers. There is no nameserver for it listed in DNS.

Code:

dig nobla.org NS

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.47.rc1.el6_8.3 <<>> nobla.org NS
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 38889
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;nobla.org.                     IN      NS

;; Query time: 2 msec
;; SERVER: 10.189.32.11#53(10.189.32.11)
;; WHEN: Tue Apr 24 15:04:54 2018
;; MSG SIZE  rcvd: 27

However, the whois record says that linode should be the NS.

Code:

jwhois nobla.org
[Querying whois.publicinterestregistry.net]
[whois.publicinterestregistry.net]
Domain Name: NOBLA.ORG
Registry Domain ID: D103425228-LROR
Registrar WHOIS Server: whois.crazydomains.com
Registrar URL: http://www.crazydomains.com
...
Name Server: NS1.LINODE.COM
Name Server: NS2.LINODE.COM
Name Server: NS3.LINODE.COM
Name Server: NS4.LINODE.COM
Name Server: NS5.LINODE.COM
DNSSEC: unsigned
URL of the ICANN Whois Inaccuracy Complaint Form: https://www.icann.org/wicf/
>>> Last update of WHOIS database: 2018-04-24T19:03:50Z <<<