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
An access port is one VLAN, usually for an end device. A trunk carries the VLANs you allow between switches or toward a router. A port that tries to be both will be the one you debug at midnight.
The allowed-VLAN builder drafts a list from ids you type. You still read it. Allowing all because the command is short is the mistake the trunk how-to also forbids.
The native VLAN, if tagged-native is not your standard, is the same on both ends. Write it. Mismatch is how traffic lands in the wrong VLAN.
Choose the word for one port. Do not reconfigure a floor from a comparison.
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.
- Pick one port.
- Say access or trunk.
- If access, write one VLAN.
- If trunk, write the allowed list and the native VLAN.
- Match the other end on paper.
- Do not apply it yet.
Mistakes that outlive the command
Trunk vs Access Ports goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- All VLANs allowed.
- Native VLAN different at each end.
- A user port left as a trunk.
- Both modes configured.
Decisions to write down
One decision for Trunk vs Access Ports: The mode is one word. The VLAN list matches the mode. Both ends agree on paper. And nothing was applied.
Checks before you call it done
Confirm this before you call the change done: The port name is written. The mode is written. The VLAN list is explicit. The native VLAN matches or is tagged on purpose. And apply waits for the how-to. If one of those fails, stop.
One port. Access or trunk.
Write the VLAN list.Before you leave the device
Trunk vs Access Ports 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.