Problems installing Ubuntu 20.04 Server

[lonewolf]

Hi All,

I'm slowly pulling what little hair I have left out. I am trying to install an Ubuntu 20.04 and 22 host.

When I get to the install place I put in my IP details and it refuses to let me install. I've tried setting up the network config file.

I cannot for the life of me get this to work.

I created a Debian VM and it worked with the same settings without a problem.

I need Ubuntu as I have 11 VM's running Ubuntu that I need to use with it.

I *THINK* it's to with the IP / Subnet. Ubuntu thinks its invalid although Debian lets it through so it works.

Lone.
Wolf Territories Grid

 

[heisenberg2980]

In that screenshot you are using a public IP address, shouldn´t you use a private one (i.e. 192.168.x.x)?

 

[lonewolf]

No it's a public IP because it's part of a public service.

 

[UdoB]

Your "gateway4" is not inside the "/24". How could it get reached???

 

[lonewolf]

Yes I know. But that's what the server farm gave me. It works under debian. But ubuntu doesn't like it.

 

[UdoB]

But that's what the server farm gave me. It works under debian. But ubuntu doesn't like it.

Interesting

Please post the output of ip address show and ip route show of the working debian VM - I am curious. And please add qm config <vmid> for both VM to compare the network.

Ubuntu does not like it because without any additional tricks it can not work...

 

[lonewolf]

Thanks so much for looking at this. Yeah if only I knew what the tricks were!

 

[UdoB]

This is another surprising combination. You need to talk to your host admin. It just does not look straight forward to me.

Sorry...

 

[lonewolf]

Thanks anyway

 

[heisenberg2980]

Yes I know. But that's what the server farm gave me. It works under debian. But ubuntu doesn't like it.

When you say "it works under debian" do you mean the server is able to reach the internet through that gateway? (i.e. can you ping google.com from the server and receive a response?)

 

[lonewolf]

Yes it works perfectly

 

[keeka]

Yes it works perfectly

The reported interface IP differs from that specified in your interface config. It could be Debian is using /etc/network/interfaces where Ubuntu 20+ is not. Network Manager or netplan maybe?
If Network Manager is active, try enabling ifupdown in /etc/NetworkManager/NetworkManager.conf.

 

[lonewolf]

Yeah it's using NETPLAN in ubuntu.

So I've posted 2 setups in this thread. 1 is the set up from a working DEBIAN installation, the other from a not working UBUNTU installation.

 

[keeka]

Yeah it's using NETPLAN in ubuntu.

So I've posted 2 setups in this thread. 1 is the set up from a working DEBIAN installation, the other from a not working UBUNTU installation.

In that case I don't believe netplan consults /etc/network/interfaces. Configure it in /etc/netplan/*.yaml or turn netplan off and use traditional ifupdown.

https://netplan.io/reference/#examples

 

[lonewolf]

interesting I'll look at that. It doesn't I have spent 3 days trying to configure it on Ubuntu with the same settings on Debian.

 

[keeka]

interesting I'll look at that. It doesn't I have spent 3 days trying to configure it on Ubuntu with the same settings on Debian.

Not saying it *is* the cause of your issue, but it has caught me out previously. I have never used netplan other than on my ubuntu desktop here. I haven't installed ubuntu server in anything other than in lxc, since 18.04. I think things changed with 20.04 and netplan came in to vogue. You can disable it but it's just as easy to configure a yaml file in the appropriate place, run 'netplan generate' and 'netplan apply'.

 

[lonewolf]

Yes, I agree normally I can configure netplan with my eyes shut and hands held behind my back, although it says its working it really isn't. And yet on the same machine, I've got a Debian VM running without a problem.

 

[keeka]

Well I guess you should determine which network management tool is controlling things. Configure in /etc/network/interfaces and reboot. Then try a yaml config for netplan and reboot. Verify the resulting interface/route/dns state are as expected following each restart. Then take it from there.

 

[lonewolf]

Okay on Debian |VM the network storage is in /etc/network/interfaces - this works
THe *SAME* settings on a different ubuntu VM in netplan.yaml do NOT work

 

[keeka]

You say same settings yet one (Debian) is configured successfully via /etc/network/interfaces and therefore ifupdown. The other (Ubuntu) unsuccessfully via netplan and /etc/netplan/*.yaml.
If you insist on using netplan, try commenting out all lines in /etc/network/interfaces, if there are any. Then use netplan to report what config is in effect and check resulting network config via the usual means.
If it still doesn't work for you, look at disabling netplan and going with traditional ifupdown and /etc/network/ config. That way you should be able to configure ubuntu identically to the way you have Debian.