Zabbix Documentation 2.0

2.23.03.44.0 (current)In development:4.2 (devel)Unsupported:1.82.02.43.2

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manual:config:items:itemtypes:simple_checks

5 Simple checks

5.1 Overview

Simple checks are normally used for remote agent-less checks of services.

Note that Zabbix agent is not needed for simple checks. Zabbix server/proxy is responsible for the processing of simple checks (making external connections, etc).

Examples of using simple checks:

net.tcp.service[ftp,,155]
net.tcp.service[http]
net.tcp.service.perf[http,,8080] 

5.2 Supported simple checks

List of supported simple checks:

Key
Description Return value Parameters Comments
icmpping[<target>,<packets>,<interval>,<size>,<timeout>]
Host accessibility by ICMP ping. 0 - ICMP ping fails
1 - ICMP ping successful
target - host IP or DNS name
packets - number of packets
interval - time between successive packets in milliseconds
size - packet size in bytes
timeout - timeout in milliseconds
Example: icmpping[,4] - if at least one packet of the four is returned, the item will return 1.

See also: table of default values.
icmppingloss[<target>,<packets>,<interval>,<size>,<timeout>]
Percentage of lost packets. Float. target - host IP or DNS name
packets - number of packets
interval - time between successive packets in milliseconds
size - packet size in bytes
timeout - timeout in milliseconds
See also: table of default values.
icmppingsec[<target>,<packets>,<interval>,<size>,<timeout>,<mode>]
ICMP ping response time (in seconds). Float. target - host IP or DNS name
packets - number of packets
interval - time between successive packets in milliseconds
size - packet size in bytes
timeout - timeout in milliseconds
mode - one of min, max, avg (default)
If host is not available (timeout reached), the item will return 0.

See also: table of default values.
net.tcp.service[service,<ip>,<port>]
Check if service is running and accepting TCP connections. 0 - service is down
1 - service is running
service - one of ssh, ntp, ldap, smtp, ftp, http, pop, nntp, imap, tcp, https, telnet (see details)
ip - IP address or DNS name (by default, host IP/DNS is used)
port - port number (by default standard service port number is used).
Example: net.tcp.service[ftp,,45] can be used to test the availability of FTP server on TCP port 45.
Note that with tcp service indicating the port is mandatory.
Note that these checks may result in additional messages in system daemon logfiles (SMTP and SSH sessions being logged usually).
Checking of encrypted protocols (like IMAP on port 993 or POP on port 995) is currently not supported. As a workaround, please use net.tcp.service[tcp,<ip>,port] for checks like these.
Services https and telnet supported since Zabbix 2.0.
Service ntp only works since Zabbix 2.0.15, despite being available in earlier versions.
net.tcp.service.perf[service,<ip>,<port>]
Service performance check. 0 - service is down
sec - number of seconds spent while connecting to the service
service - one of ssh, ntp, ldap, smtp, ftp, http, pop, nntp, imap, tcp, https, telnet (see details)
ip - IP address or DNS name (by default, host IP/DNS is used)
port - port number (by default standard service port number is used).
Example: net.tcp.service.perf[ssh] can be used to test the speed of initial response from SSH server.
Note that with tcp service indicating the port is mandatory.
Checking of encrypted protocols (like IMAP on port 993 or POP on port 995) is currently not supported. As a workaround, please use net.tcp.service.perf[tcp,<ip>,port] for checks like these.
Services https and telnet supported since Zabbix 2.0.
Service ntp only works since Zabbix 2.0.15, despite being available in earlier versions.
Called tcp_perf before Zabbix 2.0.
Timeout processing

Zabbix will not process a simple check longer than the Timeout seconds defined in the Zabbix server/proxy configuration file.

5.3 ICMP pings

Zabbix uses external utility fping for processing of ICMP pings.

The utility is not part of Zabbix distribution and has to be additionally installed. If the utility is missing, has wrong permissions or its location does not match the location set in the Zabbix server/proxy configuration file ('FpingLocation' parameter), ICMP pings (icmpping, icmppingloss, icmppingsec) will not be processed.

See also: known issues

fping must be executable by the user Zabbix daemons run as and setuid root. Run these commands as user root in order to set up correct permissions:

shell> chown root:zabbix /usr/sbin/fping
shell> chmod 4710 /usr/sbin/fping

After performing the two commands above check ownership of the fping executable. In some cases the ownership can be reset by executing the chmod command.

Defaults, limits and description of values for ICMP check parameters:

Parameter Unit Description Fping's flag Defaults set by Allowed limits
by Zabbix
fping Zabbix min max
packets number number of request packets to a target -C 3 1 10000
interval milliseconds time to wait between successive packets -p 1000 20 unlimited
size bytes packet size in bytes
56 bytes on x86, 68 bytes on x86_64
-b 56 or 68 24 65507
timeout milliseconds fping v3.x - timeout to wait after last packet sent (affected by “-C” flag)

fping v4.x - individual timeout for each packet
-t fping v3.x - 500

fping v4.x - inherited from -p flag, but not more than 2000
50 unlimited

Warning: fping defaults can differ depending on platform and version - if in doubt, check fping documentation.

Zabbix writes IP addresses to be checked by any of three icmpping* keys to a temporary file, which is then passed to fping. If items have different key parameters, only ones with identical key parameters are written to a single file.
All IP addresses written to the single file will be checked by fping in parallel, so Zabbix icmp pinger process will spend fixed amount of time disregarding the number of IP addresses in the file.