How it works
- TCP mode tries to open a connection to a host name or IP address on a port you choose.
- HTTP mode asks a web address for its headers; any answer counts, even an error page.
- It waits up to the timeout you set (3 seconds by default, 30 at most) and reports how long the answer took.
- Because a server can come up without your network changing, Wait until re-checks it on its own schedule instead of waiting for an event.
- It only checks, so it runs for real even in a dry run.
Routines that use it
Only back up when the NAS is on
If your NAS answers on its file sharing port, Move or copy file copies today's zip to it.
Wait for a game server
Wait until a server answers on its port, then Show banner tells you it's back up.
Check your home dashboard
Before Open URLs loads your home automation dashboard, make sure its address responds.
Settings
| Setting | What it does |
|---|---|
| Method | TCP: open a connection to a host and port. HTTP: ask a web address for its headers (any answer counts, even an error page). |
| Host | The host name or IP address (TCP), or the web address (HTTP). |
| Port | The TCP port. |
| Timeoutadvanced | How long to wait for an answer. |
Good to know
- HTTP mode counts any answer, so an error page still means reachable.
- The timeout can't be longer than 30 seconds.
Questions
- Can a routine ping a server before running?
- It doesn't send a ping, but Host reachable does a similar job by opening a connection on a port or asking a web address for its headers. If it answers within the timeout, the condition is true.
- Does a 404 count as reachable?
- Yes. In HTTP mode any answer means the host is up, even an error page.