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CONTENTS
14.4
Advanced ping targets
AutoPing targets don't have to be IP addresses. If you enter a hostname, it will be resolved before sending each
request. If the name resolution fails, it is assumed to be a local error and, as described
, no action is taken. If
a name is resolved to multiple IP addresses, a random one is chosen.
AutoPing defaults to checking targets using the ICMP protocol by default. A variety of other ping target kinds can
be used if you specify a URL instead of simply an IP address or hostname. Supported URL schemes include:
•
icmp
— this is explicit specification of the "regular" ping protocol, e.g.
icmp://192.168.0.1
is equiva-
lent to
192.168.0.1
(note that no trailing slash is used);
•
link
— this allows to check if the physical link is present on the wired (
link://eth0
) or wireless (
link
←
-
://wlan0
) interface (which is useful as higher-level targets will usually
link loss);
•
tcp
— this causes AutoPing to try to establish a TCP connection to the given port, e.g.
tcp
←
-
://192.168.0.1:22
can be used to check that there's a service listening on TCP port 22 (usually SSH)
of
192.168.0.1
(note that no trailing slash is used);
•
http
and
https
— this causes AutoPing to perform a HTTP/HTTPS GET request for the given URL, e.g.
http://www.digital-loggers.com/index.html
can be used to check that the web server is
responding and can serve its main page.
14.5
AutoPing events
The most often encountered AutoPing events are:
•
pinging ...
(timeout)
•
ping ...
succeeded (time)
•
ping ...
failed (time)
The time is request round-trip time, in seconds. Note that it's purely informative and can't be used as a measure of
target response time unless it has order of hundreds of milliseconds and above.
Several failures in a row trigger AutoPing actions which are reported with corresponding events:
•
item ...
(addresses...)
failed [failures/max]
•
item ...
(addresses...)
failed over (max) times in a row, disabling
As described
, local network failures don't count toward failure count, but generate these notifications
instead:
•
no usable route to host, possibly due to local network outage, not considered
a failure
(when a request isn't being sent)
•
ping ...
not received (time), possibly due to local network outage,
not considered a failure
(when an outage occurred after a request has been sent)
The events associated with item trial before enabling are self-explanatory:
•
item ...
(addresses...)
enable approved
•
item ...
(addresses...)
enable cancelled
•
item ...
(addresses...)
trial restarted due to address list changes
DLI LPC9 User’s Guide: 1.7.24.0
Summary of Contents for LPC9
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