ssh node01 ssh: Could not resolve hostname node01: Name or service not known
Which question number (which you should also include in this kind of question)? I’m going to guess Q10. If so, it worked for me when I tried it:
bob@caleston-lp10 ~ ➜ ssh bob@node01
The authenticity of host 'node01 (192.168.182.155)' can't be established.
ED25519 key fingerprint is SHA256:Yw7tfTZ52yU8lB28oE8Ej7XLiKC1T1Uu3jNYLhfc0Gk.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'node01' (ED25519) to the list of known hosts.
bob@node01's password:
Welcome to Ubuntu 22.04.5 LTS (GNU/Linux 5.15.0-164-generic x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/pro
System information as of Sat Apr 4 18:56:40 UTC 2026
System load: 0.0 Processes: 145
Usage of /: 19.4% of 9.51GB Users logged in: 0
Memory usage: 11% IPv4 address for eth0: 192.168.182.155
Swap usage: 0%
bob@node01 ~ ➜
Please give it another try; if this happened, I’d guess it was something transient.
Hi @rob_kodekloud , thank for your response.
It isn’t transient even if I try now i get the same error. And yes question 10
Hmm if i don’t attempt any question node01 is accessible. Is any of the answers to the previous question somehow impacting the local DNS? 
That had occurred to me. I don’t see anything that is likely to interfere, but that’s something to check.