Question

describe the tools used for network management

Answer 1

Answer)
The three tools used for network management and for monitor network performance are:
Wireshark - Wireshark is a free open source software for analyzing network packets, network troubleshooting, protocol development in the network of computers. Wireshark analyzes traffic and lets the user view the traffic as networks packets. Live data can be captured from networks, connections can be filtered using WireShark, captured data can be viewed and analyzed and thus can be used to analyze network security risks, threats, and gaps and can also be used in penetration testings of networks used for network scanning.
Wireshark can be used to find out the details of traffic at a variety of levels from the connection level information to the bits which make up a single packet. Thus Wireshark can be used to found out information about packets such as transmit time, source, destination, protocol type, and header data. Wireshark can also be used for evaluating security events and troubleshooting network security device issues.
tcpdump - is free computer software which works as a packet analyzer which runs on the command line and displays TCP/IP and also the other packets which are being transmitted or received over a network from and to the computer.
Nmap - is a security scanner which is used to discover hosts and services on a computer network, and thus build a map of that network. It is used for network discovery/mapping by facilitating the discovery of hosts and the services that run on them. It can be used to map the networks and determine many things about a network such as -
Type of host
Presence of a firewall
OS and version used on the host
Presence of unexpected services and hosts
and many more.......

Nmap does not detect the existence of vulnerabilities on the system. This depends on a scanning results study and a person's knowledge you may be able to identify those issues, address these issues, and improve your security as a result. Thus this doesn't help you as a vulnerability assessment assist.