Ping Monitors
A Server Monitor pings a host: on each run it sends the host a few pings and counts how many come back. Choose Server when you press New Monitor.
When ping is the right choice
Section titled “When ping is the right choice”Choose ping for a machine that answers ping and has no website or open port you want to watch, such as a network device, a gateway or a bare server.
Many hosts and cloud firewalls never answer ping. When yours has a port that takes connections, a TCP Monitor on that port answers a better question: whether the service is there, not only the machine.
A domain name or an IP address, without https:// and without a port. You cannot change it after you create the Monitor. A host that is a private address, or a name that points to one, fails: we cannot reach it from the internet.
Packet count
Section titled “Packet count”The pings sent on each run: from 1 to 10 pings, and 4 unless you change it. They are sent 1 second apart.
Maximum packet loss (%)
Section titled “Maximum packet loss (%)”The share of pings that may go unanswered on a run that still passes: from 0 to 99%, and 50% unless you change it. One ping in a few that does not come back is normal on the public internet, so the default allows for it.
A run fails when no ping comes back, or when a larger share than this goes unanswered. It can never be every ping, because a Monitor that could never fail would watch nothing.
Timeout
Section titled “Timeout”The whole run’s, not one ping’s: from 1 second to 30 seconds, and 5 seconds unless you change it. A ping that has not come back when the time is up counts as unanswered.
Because the pings go out one after another, more pings need a longer timeout. When the timeout leaves no room for the last ping, the form says the shortest it allows for your packet count.
The test before you create it
Section titled “The test before you create it”A host that does not answer ping looks exactly like a host that is down, and only a test from us can tell the two apart. So a Server Monitor needs a test before you create it.
Press Test, and one location sends the pings once. You can create the Monitor once at least one ping came back.
- When more went unanswered than your maximum allows, the test says so, and you can still create the Monitor. The network may be poor for a moment, but a host that ignores ping never answers at all.
- When no ping came back, the host may be filtering ping. A TCP Monitor on a port it listens on answers a better question.
- When the location did not answer in time, test again.
Change a setting and the test is needed again.
Its Checks
Section titled “Its Checks”A Server Monitor carries the Uptime and the Performance Check. Its answer time is the quickest any ping of the run took to come back.