What are the most effective LAN-WAN troubleshooting tools and techniques?

1 Ping and Traceroute

Ping and traceroute are two basic but essential tools that can help you test the reachability and latency of a network. Ping sends a packet of data to a destination IP address and waits for a response. It measures the round-trip time and reports any packet loss. Traceroute shows the path that a packet takes from the source to the destination, and displays the IP addresses and names of each hop along the way. It also measures the time it takes for each hop. Ping and traceroute can help you verify if a network device is online, locate the source of a network delay, and identify any routing issues.

2 Wireshark and Tcpdump

Wireshark and tcpdump are two powerful tools that can help you capture and analyze network traffic. Wireshark is a graphical user interface (GUI) tool that allows you to filter, sort, and display network packets in various formats. Tcpdump is a command-line tool that allows you to capture and dump network packets to a file or standard output. You can use Wireshark and tcpdump to monitor the network activity, inspect the packet contents, and troubleshoot network errors. For example, you can use them to check the TCP handshake, detect packet retransmissions, and identify malicious traffic.

3 SNMP and NetFlow

SNMP and NetFlow are two protocols that can help you collect and manage network data. SNMP stands for simple network management protocol, which is a standard for communicating with network devices and retrieving information about their status, configuration, and performance. NetFlow is a protocol that records and exports information about the network traffic flows, such as the source and destination IP addresses, ports, protocols, and bytes. You can use SNMP and NetFlow to monitor the network health, utilization, and behavior. For example, you can use them to check the device availability, bandwidth consumption, and traffic patterns.

4 Nmap and Telnet

Nmap and telnet are two tools that can help you scan and access network devices. Nmap is a tool that can discover and map network hosts, ports, services, and vulnerabilities. It can perform various types of scans, such as ping scan, port scan, service scan, and OS scan. Telnet is a tool that can establish a remote connection to a network device using the telnet protocol. It can allow you to log in and execute commands on the device. You can use Nmap and telnet to explore and test the network security, functionality, and configuration. For example, you can use them to find open ports, identify running services, and verify device settings.

5 IP SLA and Netcat

IP SLA and netcat are two tools that can help you measure and simulate network performance. IP SLA stands for IP service level agreement, which is a feature that can generate and monitor synthetic network traffic. It can measure various metrics, such as jitter, latency, packet loss, and response time. Netcat is a tool that can create and manipulate network connections. It can send and receive data, listen and connect to ports, and act as a client or a server. You can use IP SLA and netcat to evaluate and emulate network scenarios, such as voice over IP (VoIP), file transfer, and web browsing. For example, you can use them to test the quality of service (QoS), transfer files, and create backdoors.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?