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
Private ranges are 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16. You may use them inside your network. You do not advertise them to the internet as if they were yours.
Documentation ranges and CGNAT space 100.64.0.0/10 are not free LAN space. A bogon is a prefix that should not appear as a source from the internet. The checkers identify a lab address you type. They do not scan a network.
An address can be private and still be the wrong site's private address. Overlapping 10/8 between two companies is a VPN problem you write down before you connect them.
This page does not geolocate a person and does not tell you that an address is safe to attack. Identification is so you label your own plan.
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.
- Type one address you are allowed to handle.
- Read the label the checker gives.
- Write private, public, documentation, or CGNAT.
- If it is someone else's public address, stop.
- Do not advertise a private prefix.
- Hand overlapping private space to the VPN design.
Mistakes that outlive the command
Private vs Public IP Ranges goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Advertising 10/8 upstream.
- Using 192.0.2.0/24 in production.
- Treating CGNAT as a private LAN.
- A lookup of an address you have no reason to hold.
- Calling a label a permission to probe.
Decisions to write down
One decision for Private vs Public IP Ranges: The address is one you may hold. The label is written. Private space is not advertised. Documentation ranges stay in notes. And no probe follows the label.
Checks before you call it done
Confirm this before you call the change done: One address was classified. The label is in the ticket. No scan was run. A private prefix was not advertised. And the next step is design, not a probe. If one of those fails, stop.
Classify one address you may hold.
Do not scan from the label.Before you leave the device
Private vs Public IP Ranges 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.
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