Hello Alan,

On Tuesday, 22 August 2023 14:00:26 BST Alan Mackenzie wrote:

> I don't understand what I just did, by deleting net.enp38s0, though it
> appeared to have fixed the problem.  That worries me.  Could you possibly
> explain to me a bit more what that removal did?  Thanks!

There are different ways to configure and bring up your network interface.

If you have a complicated network configuration, with static address(es), 
bridges, multihoming, etc. then using netifrc scripts is a convenient method 
to automate default runlevel service(s) to manage your setup.

For simpler network requirements a dhcp client, like dhcpcd, is adequate for 
bringing up and configuring your network interface.

In absence of any manual settings netifrc will also bring up dhcpcd to try to 
obtain an IP address from the router.

You had both a netifrc service and a dhcpcd service starting up, each trying 
to negotiate an IP address from your router and tripping over themselves.


> On removing dhcpcd from default, the maching just has no network
> connection on booting up.

OK, sometimes a service which requires a network connection can bring in 
dhcpcd - I have neither netifrc nor dhcpcd services starting here on their 
own:

 $ rc-update -s -v | grep 'dhcpcd|net'
               dhcpcd |                                        
                local |      default nonetwork                 
           net-online |                                        
               net.lo |                                        
             netmount |      default 

but in my case I think chronyd starts dhcpcd to connect to the network.

In your case, dhcpcd launched as a default service is needed to set up your 
connection.