This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
DHCP is discover, offer, request, acknowledge. The scope calculator drafts a pool from a prefix and reservations you type. The option reference names options such as gateway and DNS. Neither tool runs a server.
The pool must not include the gateway or servers you made static. Write the exclusions. A lease time is a choice. A day is a fine lab. A minute is a way to fill a log.
A scope on a VLAN you have not counted will collide. Use a lab VLAN. The vendor page configures it later.
Do not capture client traffic to watch the handshake on a production VLAN for practice.
The change you can finish
Apply nothing during the writing of the note. When the lab window opens, it is one change on the device named in the ticket. Read the draft, then the device, then decide.
Rollback is the file or the revision you saved first. You do not invent a rollback after the only copy is gone.
- Name the VLAN and the prefix.
- Exclude static addresses.
- Name the gateway and the DNS you will hand out.
- Pick a lease time.
- Keep it on a lab VLAN.
- Do not start a server on this page.
Mistakes that outlive the command
DHCP Explained (DORA Process) goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- The gateway inside the pool.
- A production VLAN used as the lesson.
- A one-minute lease.
- Two servers on one VLAN without a sentence.
- A capture of user handshakes for practice.
Decisions to write down
One decision for DHCP Explained (DORA Process): Exclusions include the gateway. DNS and gateway are named. The VLAN is a lab. The lease is reasonable. And no server was started.
Checks before you call it done
Confirm this before you call the change done: The prefix and exclusions are written. Options are named. The VLAN is a lab id. No production scope was created. And configuration waits. If one of those fails, stop.
Exclude the gateway from the pool.
A lab VLAN only.Before you leave the device
DHCP Explained (DORA Process) ends when the hostname on the device matches the hostname in the ticket. If it does not, you are on the wrong box. Stop. A command that succeeded on the wrong box is not progress.
The draft stays a draft until a person has read the names in it. A generator does not log into the device and does not know which interface is the uplink. You delete a line that names a device, a zone, or a prefix you did not write down.
0.0.0.0/0 is not kept because a sample included it. A source you can say is the source you keep. 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. They belong in the note. They are not prefixes you type onto a production device because they appeared in a draft.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, a community string, or a pre-shared key you save in the ticket or in git. The real secret stays in the store.
One change is the window. A VLAN and a routing protocol and a VPN do not share it. If two things move and the result is wrong, you will not know which one did it. The next feature waits for its own page.
If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied config produces a device nobody can rebuild. Restore the copy you took first.
A second person reads the device name and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the device alone.
This page is a planning guide. It is not a vendor manual, not an official standard, and not a permission to touch a network you do not administer. The pillar guide owns the wider design. This page owns one lab proof.
Tools for this guide
These tools run in the browser on this site. They do not log into your machines.
Related pillar guides
More in this cluster
The pillar for this page, and the next published pages filed with it.