Internet Control Message Protocol, or ICMP, is one of the protocols used to pass diagnostic messages between network devices. For example, if there’s problem locating the target network device we are trying to connect to, an ICMP message can be sent to indicate the error. There are but few programs utilizing ICMP, one of them being ping utility.
Ping is a simple means to check for a network device presence and evaluate an average round-trip time. It sends an echo request ICMP message and waits for the response. Ping is one of the base tools to analyze network status and connectivity; however, echo responses are often blocked by firewalls, making ping unable to communicate with such devices. Checking for host presence via ping isn’t reliable; other testing means are required to actually test connectivity and validity of response.
SNMP Custom Monitoring
The monitoring list includes network devices of many types. SNMP uses a hierarchy of OIDs ( object identifiers) assigned and registered (see IANA OID registry); …