Network Tools for Troubleshooting

AI Strategy umais20@yahoo.com January 03, 2026
Host-Based Command Line Mastery

Beyond Nmap: Essential native tools for troubleshooting, forensics, and network mapping.


In a Security+ Performance Based Question (PBQ), you are often dropped into a terminal and told to "identify the malicious connection" or "fix the DNS resolution." You won't always have Nmap. You must master the native binaries built into Windows, Linux, and macOS.

1. netstat (Network Statistics)

Exam Scenario: "Identify which local process is communicating with a known malicious IP address on the internet."

netstat -ano
  • -a: Displays all active connections and listening ports.
  • -n: Displays addresses and port numbers in numerical form (no DNS lookup).
  • -o: Shows the PID (Process ID) associated with each connection.

Guru Tip: Once you find the PID in netstat, use tasklist (Windows) or ps (Linux) to find the name of the actual malware file.

2. Domain Diagnostics: NSLOOKUP & DIG

When the network is "slow" or "down," it’s often a DNS issue. Security+ requires you to know how to query specific records.

nslookup (Windows/Linux)

Used to query DNS servers. To check a specific record type (like a Mail Server):

nslookup -type=mx google.com
dig (Linux/macOS)

The "Domain Information Groper." More detailed and powerful than nslookup:

dig google.com ANY

3. Path Analysis: tracert & pathping

If you suspect a "Man-in-the-Middle" attack or a routing loop, you need to see every hop between you and the target.

Command OS Benefit
tracert Windows Uses ICMP to show the path to a destination.
traceroute Linux/Mac Uses UDP packets to map the network path.
pathping Windows Combines ping and tracert to show packet loss at specific hops.

4. arp (Address Resolution Protocol)

Crucial for detecting ARP Poisoning or Spoofing attacks.

Command: arp -a

Security+ Catch: If you see two different IP addresses associated with the same MAC address in the ARP table, you are likely the victim of a Man-in-the-Middle attack.

The Troubleshooting Checklist

Next time you face a connectivity issue, run these in order:

ipconfig / ifconfig ping nslookup netstat

Master these, and the PBQs will be the easiest part of your exam.

Community Discussion (0)

Leave a Comment

No approved comments yet. Be the first to start the conversation!

Heartbeat Assistant