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
A looking glass shows what a public collector sees for a prefix you ask about. The tools query that public data or compare a paste. They do not open a session with your router. A prefix you do not originate is not a route you may announce because it appeared.
One prefix you were assigned, or a documentation prefix labeled as an example. Write the time. Public answers change. Do not use the result as a map of a network you do not administer.
Visibility is not reachability you can promise, and it is not a person.
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 prefix you originate, or label a documentation example.
- Read the answer.
- Write the time.
- Do not announce a foreign prefix.
- Do not open a session.
- Stop.
Mistakes that outlive the command
BGP Looking Glasses Explained goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Announcing a prefix from the answer.
- A new BGP session.
- A list of other networks mapped for its own sake.
- Calling the answer a person.
Decisions to write down
One decision for BGP Looking Glasses Explained: The prefix is yours or labeled as an example. No route was announced. No session was opened. The time is written. And the answer is not an identity.
Checks before you call it done
Confirm this before you call the change done: The prefix is written. The answer is written. The time is written. No session was configured. And no foreign prefix was announced. If one of those fails, stop.
Before you leave the device
BGP Looking Glasses Explained 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.