[Feedback]: Instructions for netboot server installer do not cover common use case, and do not describe network and server requirements very well

### Page URL

https://ubuntu.com/server/docs/how-to/installation/how-to-netboot-the-server-installer-on-amd64/

### Select an option

- [ ] I found what I was looking for
- [ ] I couldn't find what I was looking for
- [x] I found the information, but it was incorrect
- [x] I found the information, but it was incomplete
- [ ] I found the information, but it was confusing
- [ ] I encountered a technical issue (e.g., broken link, image not loading)

### Issue Description

This doc is helpful, but does not cover

* Do I need a separate server for this? What are my hardware and network topology minimum requirements?
* What if I have a DHCP server already on this network?

Additionally there are essentially no troubleshooting suggestions. I got errors and conflicts on ports and ip addresses until I made some critical changes.

Start with the netboot server installer page at the reported URL and review its current setup instructions. Document the needed hardware and network topology, explain how an existing DHCP server affects the setup, and add troubleshooting guidance for the reported port and IP-address conflicts; the page should answer these questions without requiring trial and error.

Written by the indexing model from the issue text.