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
RADIUS is commonly used for network access and for admin login. TACACS+ separates authentication, authorization, and accounting more clearly and is often the admin protocol on network devices. The attribute reference is a lookup. It does not create a user.
The server is one you operate. A shared secret in the draft is prompt-for-this. The local admin on the device remains, so a dead server does not lock every operator out. Do not remove that local account in the same window.
One device class. Command authorization, if you want it, is a later proof. This page chooses the protocol and the failure behavior.
Do not point a device at a server you do not administer to see what it returns.
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 device class.
- Choose RADIUS or TACACS+.
- Name the server you operate.
- Keep the local admin.
- Replace the secret with prompt-for-this.
- Do not retarget production in this hour.
Mistakes that outlive the command
RADIUS vs TACACS+ goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- The local admin removed.
- A secret saved in the note.
- A server you do not operate.
- Every device class changed at once.
- Command authorization enabled unread.
Decisions to write down
One decision for RADIUS vs TACACS+: The server is yours. The protocol is one choice. Break-glass remains. The secret is not in the note. And production waits.
Checks before you call it done
Confirm this before you call the change done: The protocol is written. The server is named. The local account is still in the plan. No secret was saved. And no device was retargeted. If one of those fails, stop.
| Protocol | Often used for | You still keep |
|---|---|---|
| RADIUS | Access and many admin logins | A local break-glass account |
| TACACS+ | Device admin with command accounting | The same local account |
Before you leave the device
RADIUS vs TACACS+ 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.
- Pillar: Network Security & VPN Guide
- Comparison: 802.1X EAP Methods Compared
- Explainer: Zero Trust Network Access (ZTNA) Explained
- Explainer: Microsegmentation Explained
Companion: System: Active Directory Fundamentals.