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
Bridge, host, and an overlay are different places for a container's packets. The planner drafts a mode. It does not start a container. Host mode shares the host's network namespace, which is a large choice. Write why you need it, or do not choose it.
A published port is a listen on the host. 0.0.0.0 is the usual default and it is a default you narrow to the prefix that should reach the service. Do not publish management to the world.
The lab host is yours. A container bridge onto the office VLAN will take addresses and answer neighbors. Keep the lab on its own bridge unless a written ticket says otherwise.
Image sources and registry credentials stay out of the note.
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 lab host.
- Choose a mode and write why.
- If you publish a port, name the source prefix.
- Keep the lab off the office VLAN.
- Remove credentials from the note.
- Do not start a production container from this page.
Mistakes that outlive the command
Docker Networking Explained goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- Host mode with no reason.
- A port published to the world.
- The lab bridged to the office VLAN.
- A registry password in the file.
- A container started on a host you do not administer.
Decisions to write down
One decision for Docker Networking Explained: The host is yours. The mode has a reason. Published ports are limited. The office VLAN is not the lab. And no credential was saved.
Checks before you call it done
Confirm this before you call the change done: The mode is written. The port and the prefix are written. The bridge is the lab. Credentials are absent. And production was not started. If one of those fails, stop.
Before you leave the device
Docker Networking 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.
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.