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Fresh install as a server: No response from server

We setup nextdns on an ubuntu machine as router/server mode. 

nextdns status
running

nextdns version
nextdns version 1.43.5

We configured a static block domain in our profile and it seems to work fine from the ubuntu machine:

nslookup ebay.ch
Server:         127.0.0.1
Address:        127.0.0.1#53

Non-authoritative answer:
Name: ebay.ch
Address: 0.0.0.0
Name: ebay.ch
Address: ::

If we resolve something else, it resolves fine and we can see the domain in the log of the management web interface online.

nslookup facebook.com
Server:         127.0.0.1
Address:        127.0.0.1#53

Non-authoritative answer:
Name: facebook.com
Address: 157.240.17.35
Name: facebook.com
Address: 2a03:2880:f15b:83:face:b00c:0:25de

So we are sure that the link from the ubuntu machine to the nextdns  cloud works fine. But the problem is, if we try to resolve something from the client, we get the response that the server could not resolve the domain. 

C:\Users\userA>nslookup
> server 172.16.20.168
Standardserver:  [172.16.20.168]
Address:  172.16.20.168

> google.com
Server:  [172.16.20.168]
Address:  172.16.20.168

*** google.com wurde von [172.16.20.168] nicht gefunden: No response from server.

So this is not a timeout but a precise response from the server. If the DNS service would not run on the ubunutu box, we would get timeouts and retries. Strange thing here is, that the DNS service is only listening on the loopback IP address and not the IP of the interface ens192.

ss -tulw | grep domain
udp   UNCONN 0      0                  127.0.0.1:domain         0.0.0.0:*          
udp   UNCONN 0      0                 127.0.0.54:domain         0.0.0.0:*          
udp   UNCONN 0      0              127.0.0.53%lo:domain         0.0.0.0:*          
tcp   LISTEN 0      4096               127.0.0.1:domain         0.0.0.0:*          
tcp   LISTEN 0      4096              127.0.0.54:domain         0.0.0.0:*          
tcp   LISTEN 0      4096           127.0.0.53%lo:domain         0.0.0.0:*

So what are we missing here?

3 replies

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    • NextDNs
    • 3 mths ago
    • Reported - view

    Did you set “setup-router” configuration directive to true?

    • Patrick_Fisher
    • 3 mths ago
    • Reported - view

    So i was installing it as a router with this config lines:

    sudo nextdns install \
  -profile <your profile id> \
  -report-client-info \
  -setup-router

    But you are right, if i check the configuration, the setup-router flag was set to false. i changed it to true and restarted nextdns by issuing nextdns stop and nextdns start but somehow i have the same behaviour still. No response from server when i try to querry from a client. This is the current config:

    root@dns01:~# nextdns config list
    cache-max-age 0s
    detect-captive-portals false
    bogus-priv true
    debug false
    profile 4xxxx4 <--- hidden
    hardened-privacy false
    timeout 5s
    setup-router true
    cache-size 10MB
    max-ttl 0s
    report-client-info true
    mdns all
    use-hosts true
    auto-activate true
    listen localhost:53
    log-queries false
    discovery-dns 
    control /var/run/nextdns.sock
    max-inflight-requests 256

    Anything else wrong on this config?

    • Patrick_Fisher
    • 2 mths ago
    • Reported - view

    After a complete reinstall of the OS and nextdns, everything worked fine on the second try. Dont know what went wrong on the first try, but im glad it works now.

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Content aside

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