Domain Join Ubuntu 22.04 - Failed (with updated Join Script)

UCS - Univention Corporate Server
10

I goofed up again and missed some 4 in my command; please re-run this again with the fixed name ucs-1234:

dig +short -p 53 @127.0.0.53 ucs-1234.codenauten.intranet. any  # ❓
dig +short -p 53 @192.168.2.1 ucs-1234.codenauten.intranet. any  # ❌
dig +short -p 53 @IP.of.your.UCS ucs-1234.codenauten.intranet. any # ✅

The last one I expected, the first one is also good as this shows me that your locally running DNS service is able to resolve the SRV records. But this contradicts the message from the log-file from above:

2022-11-23 22:18:18,657 userinfo CRITICAL All nameservers failed to answer the query _domaincontroller_master._tcp.codenauten.intranet. IN SRV: Server 127.0.0.53 UDP port 53 answered SERVFAIL

Now I hope that the commands to resolve that name to IP addresses above work the same.

Can you please check the content of /etc/resolv.conf that is contains the line

nameserver 127.0.0.53

It probably is a symbolic link to /run/NetworkManager/resolv.conf which NM auto-generates.

Can you also please run this command:

getent ahosts ucs-1234.codenauten.intranet.

It should also be able to resolve the name into IP addresses. Sadly there are many implementations of the DNS resolution mechanism, which all use the same underlying DNS service, but they all differ in nuances and may return different results. So next also give this a try:

python3 -c 'from dns.resolver import Resolver;r=Resolver();print(r.query("_domaincontroller_master._tcp.codenauten.intranet.","SRV"))'
python3 -c 'from dns.resolver import Resolver;r=Resolver();print(r.query("ucs-1234.codenauten.intranet.","A"))'

You have to copy the filed to your server and configure Apache to use them. See Using your own SSL certificates

FYI: There’s also our Let’s encrypt App in our app-center which you could have used to generate those certificates.

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