# Update your IP from a computer

> When your router can't do dynamic DNS, any computer on the same connection can do it instead — on a schedule, in the background.

Source: https://infranest.io/docs/dynamic-ip-from-a-computer
Last updated: 2026-09-19

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Keep your Dynamic IP record current by having a computer on the same connection check in automatically, on a schedule — useful when your router can't do this itself. This is for anyone whose router doesn't support dynamic DNS but who has a laptop, NAS or small server that's usually switched on.

## Overview
- Any computer on the connection can report the address, since what gets recorded is the connection's address, not the computer's own.
- Pick a machine that's usually on — a laptop, a NAS or a small server all work equally well.
- The update runs in the background on a schedule you set, using a command copied from InfraNest.

## Get the command
1. Open **Dynamic IPs**, select your Dynamic IP, then go to **Setup**.
2. Choose **Command line** at the top of the page.
3. Copy the complete command shown — it already includes your details. You'll paste it into a scheduler below.
4. Optionally, run it once to confirm everything works — this updates your address immediately, before you schedule it.

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> [!NOTE]
> The command contains your password. Anyone who can read the file or task you save it in can use it, so keep it somewhere only you can read.

## How often to run it
Every five minutes is a sensible default. Calling more often achieves nothing — updates only happen when the address actually changed — and calling much less often means a longer gap between your address changing and your records catching up.

## Schedule it on Linux (cron)
1. Run `crontab -e`.
2. Add a line like:
```
*/5 * * * * curl -sS -u 'USERNAME:PASSWORD' 'https://YOUR-SERVER/' >/dev/null 2>&1
```
3. Replace the whole `curl …` part with the command copied from the Setup tab.
4. Save and close the file — cron picks it up straight away.
5. To confirm it's running, temporarily remove `>/dev/null 2>&1` and check your mail or the cron log. A working call replies with `good` followed by your address, or `nochg` if it hasn't changed.

## Schedule it on macOS (cron)
macOS still has cron, and it's the simplest option — the Linux instructions above apply exactly.

If you'd rather use launchd, Apple's preferred scheduler:
1. Create a Launch Agent file in `~/Library/LaunchAgents/`.
2. Have it run the same command, with `StartInterval` set to `300`.
3. Load it with `launchctl load`.

Both approaches work; cron needs less setup.

> [!NOTE]
> On a laptop, neither scheduler runs while the machine is asleep. That's usually fine, since nothing needs updating while you're not connected, but the first update after waking may take a few minutes.

## Schedule it on Windows (Task Scheduler)
Windows has no built-in dynamic DNS client, so a scheduled task is the way to go.

1. Open **Task Scheduler** and choose **Create Task** (not the basic wizard — you need the extra options).
2. On the **General** tab, tick **Run whether user is logged on or not**.
3. On the **Triggers** tab, add a trigger: **At startup**, then tick **Repeat task every 5 minutes** for a duration of **Indefinitely**.
4. On the **Actions** tab, add an action that starts `powershell.exe` with arguments along these lines, using the values from the Setup tab:
```
-NoProfile -WindowStyle Hidden -Command "Invoke-WebRequest -Uri 'https://YOUR-SERVER/' -Credential (New-Object PSCredential('USERNAME',(ConvertTo-SecureString 'PASSWORD' -AsPlainText -Force))) -UseBasicParsing"
```
5. Select **Save**. Windows will ask for your account password so the task can run in the background.
6. Use **Run** on the task once to confirm it works, then check the Setup tab — it should show the check-in within a few seconds.

## Confirm it's working
1. Go back to the Setup tab.
2. Look at **Has your router reached us?**. It shows when the last call arrived, from which address, and whether the password was right.
3. Leave the tab open — it updates by itself.

## Tips
> [!TIP]
> Run the command once by hand before scheduling it — it's the fastest way to confirm your details are correct.