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 local forward accepts a port on the SSH client and connects it, from the server, to a host the ticket names. A remote forward does the reverse. A dynamic forward is a SOCKS proxy on the client. The builder drafts text. It does not log in.
You use a forward only between hosts you administer, for a port the ticket names. If the draft reaches a network you do not run, delete that line. A tunnel is not a way around a control on a network you do not administer, and this page does not describe that use.
The SSH login itself still needs a named account and a secret that stays in the store. prompt-for-this is not a password. Management of the jump host stays on the prefix you already allowed.
One forward. A capture of the tunnel is a different page and only for traffic you were asked to take.
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 client and the server you administer.
- Name the one port.
- Draft the command and read the target.
- Delete any host you do not run.
- Keep the secret out of the note.
- Do not point the forward at a network you do not administer.
Mistakes that outlive the command
SSH Tunneling Explained goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- A forward into a network you do not run.
- A tunnel used to evade a control elsewhere.
- A password in the ticket.
- Several ports because the builder allowed them.
- A capture you were not asked to take.
Decisions to write down
One decision for SSH Tunneling Explained: Both SSH ends are yours. One port is named. Foreign targets are deleted. The secret is not in the note. And evasion is not the use.
Checks before you call it done
Confirm this before you call the change done: The hosts are written. The port is written. The draft was edited. No foreign target remains. And no login was made from this page. If one of those fails, stop.
Before you leave the device
SSH Tunneling 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.
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