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
fail2ban drafts a jail. The SSH changes that belong in the ticket are a named admin, keys, and no password login from every address. A console or a second session is written down before any later apply.
You do not change the port and close the session you are using. You do not disable the firewall.
192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the system named in the ticket. Read the draft, then the system, then decide.
Rollback is the file, the record, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Name the host and the admin.
- Read the jail draft.
- Write the console path.
- Do not apply during the reading.
- Stop.
Mistakes that outlive the statement
SSH Hardening Guide goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Root login left open to every address.
- The only session used for the change.
- The firewall disabled.
Decisions to write down
One decision for SSH Hardening Guide: A console path is written. Root login from every address is absent. And nothing was applied.
Checks before you call it done
Confirm this before you call the change done: The host is written. The console path is written. The draft was read. Nothing was applied. And the host is yours. If one of those fails, stop.
# SSH hardening. Keep a console path. Do not apply during the reading.
# 192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.Before you leave the system
SSH Hardening Guide ends when the system in the note is the system in the ticket. If it is not, stop.
The draft stays a draft until a person has read the names in it. A generator does not log in, does not scan, and does not send mail.
192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you publish because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save. A sample password is replaced. It is not a password you keep.
One change is the window. If two things move and the result is wrong, you will not know which one did it.
If the same step fails twice, stop for the day. Restore the copy you took first.
A second person reads the scope aloud. If they cannot find it in the ticket, the note is not done.
This page is a planning guide. It is not legal advice, not an audit opinion, not a vendor manual, and not the text of a standard. You do not disable a security control to make a check pass. You do not use the page against a system you do not administer.
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.
- Pillar: Server Hardening Guide
- How-To: Sysmon Setup Guide
- Explainer: Attack Surface Reduction Rules Explained
- How-To: Writing Suricata and Snort Rules
Companion: System: SSH Key Authentication Setup Guide.