Cisco IOS Hardening Checklist

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

The audit tool reads a config you paste. Paste a config you are allowed to hold, with secrets removed. If a secret is in the file, rotate it and redact before you continue. The tool does not log into the router.

One gap is the result: Telnet still on, a type 7 secret, SNMP public, or management from any source. Write it. The fix is the SSH and hardening how-to, later, with a second session.

This list is not a certification and not a CIS attestation. The security desk's hardening guide is the neighbour. An auditor sees your ticket, not this paragraph.

Do not disable logging to clear a line. Do not paste someone else's config.

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.

Confirm the device is yours.
Redact secrets. Rotate any you found.
Run one reading.
Choose one gap.
Name the later fix.
Do not call the result a certification.

Mistakes that outlive the command

Cisco IOS Hardening Checklist goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

A certification claimed.
Someone else's config.
A secret left in the paste.
Logging disabled to pass.
Every finding fixed in one session.
The only management session used to tighten access.

Decisions to write down

One decision for Cisco IOS Hardening Checklist: The device is yours. Secrets are redacted. One gap is written. The result is not a certification. Logging stays on. And the fix is later.

Checks before you call it done

Confirm this before you call the change done: The gap is one sentence. The fix page is named. No login was made by the tool. No certification is claimed. And a second session is planned before access is tightened. If one of those fails, stop.

One gap. Not a certification.
Redact secrets before you paste.

Before you leave the device

Cisco IOS Hardening Checklist 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.

Cisco IOS Config Security Audit

Network Device Hardening Guide

More in this cluster

The pillar for this page, and the next published pages filed with it.

Companion: Security: Server Hardening Guide.