I run my Home Assistant in a Proxmox VM (x86 based) with HAOS. The VM contains two network cards because I use two VLANs for my smart home: the regular network and a devices network.
As my network setup is not basic in general at home, I run a dedicated DHCP server (isc-dhcpd 4.4.3) on my network router, and from time to time I check its logs, especially when I update my configuration e.g. for new devices with fixed IP addresses.
This way I found out that my home assistant instance sends out DHCPDISCOVER messages for its devices network card every 2 to 15 seconds - and most of the time it gets back the same IP address since the lease is not yet expired.
I would like to find out the reason for this behaviour as it is only happening on the devices network and not on the regular network, although I set them up both in a similar way.
Can you guide me how to find out more about this phenomenon? The system is running fine but from my experiences with IT systems I just have a bad feeling. Are there any (debug?) logs I could check, any configs I could fiddle around with to see if the DHCP messages stop?
From searches in the forum I found that it could have to do with DHCP discovery, but why does it only happen on one of the interfaces and why would discovery send out messages instead of just listening?
My configs are quite basic, I have only a handful of official extensions + Tailscale, Zigbee2MQTT and HACS (I needed the latter to run a ZHA to Zigbee2MQTT conversion script once, no extra apps downloaded from there).
What additional information shall I provide here to make analysis easier?
Hope that somebody has an idea what causes those mysterious messages. Config issue or bug? My best guess would be PEBKAC 
Cheers,
cyberbrain