Network Monitoring involves using different hardware and software tools (Systems) or both to continuously observe the status of network devices or hosts, and notify the network administrator through email, SMS or other alarms in case of error or failure. This may happen when network monitoring software observe the status of network devices or host speaks with their corresponding protocols within the Open System Interconnection Model stack (OSI Layer).The aim of this paper is to explain important concepts used in implementing software for monitoring hosts and network devices to inexperienced programmers and researchers. This paper explains how a Simple network Management Protocol (SNMP), Internet Control Message Protocol (ICMP), Dynamic Host Control Protocol (DHCP), Domain Name Service (DNS), Hypertext Transfer Protocol (HTTP), Management Information Base (MIB) and Port Scanning concept can be implemented to form up a network monitoring software. During implementation, the following software have been suggested, Java NetbeansIDE for the Java programming platform, Manage engine for Identifying SNMP Object Identifier (OID) numbers and their meaning from network devices and hosts, and SNMP for Java (SNMP4J) Application Program Interface (API) for providing SNMP Libraries for the Netbeans IDE.