While a Zabbix agent offers great features on most platforms, in some cases it is not possible to install it. For these cases, some agentless monitoring methods are provided by the Zabbix server.
|Network Services Check||
A Zabbix server can check if a service is listening on a port, and also checks that it is responding properly. This method is currently supported for the following services: FTP, IMAP, HTTP, HTTPS, LDAP, NNTP, POP3, SMTP, SSH, TCP and Telnet.
TCP port check
For cases not handled by the previous item, Zabbix server can check if there is something listening on a TCP port, informing if a service is available or not.
Although simple, but important, Zabbix can check if a host is responding to ICMP ping packets. Thus, it is possible to control the availability of a server, as well as the response time and packet loss.
Checks can be customized by setting the size and number of packets, timeout and delay between each packet.
SSH and Telnet
When the configuration of a Zabbix agent is not possible, but access via SSH or Telnet is available, a Zabbix server can run any custom command and use its return as a value collected. From this value it is possible, for example, to generate graphs and alarms.