Dns Dhcp Ipam

Operate DNS, DHCP, and IPAM as one system. Use when a scope is exhausted, a resolver is poisoned, or a split-horizon zone is drifting from NetBox.

gesh75 Updated

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DNS DHCP IPAM

Do not use for recursive resolver software internals. Not for public DNS marketing records.

Procedure

  1. NetBox is authoritative for prefixes and names. DHCP scopes are carved from NetBox, not from a spreadsheet.
  2. Resolvers anycasted (TCP/UDP 53) behind two sites. Health-check the service, not just the VIP.
  3. Split horizon: internal views never leak. External views never contain RFC1918.
  4. Exhaustion: 80% lease use is a project, 95% is an incident. Scavenge stale first.
  5. Verify: dig +norecurse against each NS, a new lease on a test port, PTR matches A.
scope 10.24.12.0/24  leases 231/250  92%
  action: reclaim 14 declined  then expand from netbox prefix

Anti-patterns

  • Never add a forwarder to 8.8.8.8 "just for this app".
  • Do not hand out public DNS as the only campus resolver.

Safety

Zone edits are reviewed. DHCP option 43/66 changes can take a building down — twin first.

gesh75/claude-skill-lint/tree/main/skills/netops/dns-dhcp-ipam commit 64d264bc11

Frequently asked questions

npx skillmds@latest add gesh75/dns-dhcp-ipam