I've documented my Proxmox cluster, switch connections, inter-switch links, DHCP configuration, DNS zones, and forwarding rules. The remaining task is documenting every IP address on the network, but manually reconciling everything has led to mistakes and repeated rechecking. Would combining DHCP leases, DNS records, Nmap service scans, and manual lookups produce a reliable inventory, or is there a better workflow and tool for maintaining it?
3 Answers
The first documentation pass is usually the most difficult. A spreadsheet can help you establish and clean up the initial baseline, but moving it into a purpose-built IPAM tool will make ongoing maintenance much easier. After that, schedule regular DHCP collection and network discovery scans, and generate drift reports instead of rebuilding the inventory by hand.
The important part is deciding what you actually want to document and how the records should be organized. Once that model is clear, scripts can collect information from DHCP, DNS, switches, hypervisors, and scans on a schedule. Add alerts when collection fails, and use the results to identify discrepancies rather than automatically overwriting your authoritative records.
Use NetBox or phpIPAM as the source of truth instead of maintaining several separate lists. DHCP leases, DNS records, and Nmap scans each show a different part of the network: DHCP won’t show static devices, DNS can be out of date, and Nmap won’t find powered-off or firewalled systems. Treat those systems as data feeds that you compare against the inventory, then investigate anything that appears on the network but isn’t documented.
So should I build and verify the initial baseline in a spreadsheet first, then import it into NetBox?