Networking basics for Service Desk: Ping, Tracert and DNS

When a user reports that “the internet isn’t working,” or they can’t connect to a key corporate server, as a Service Desk agent, you must quickly figure out where the problem is. Is the error at the user’s home on the router? In our corporate VPN? Or with the ISP?

Three absolute basics of network troubleshooting answer these questions: ping, tracert, and understanding DNS.

1. My best friend: PING

Ping determines if the target device is reachable and how long it takes for our packet to get there and back. It works on the principle of an echo delivered by the ICMP protocol.

A practical example:

1. A user says they can’t open intranet.company.org.
2. I try to ping 8.8.8.8 (Google DNS). If a response comes back within a few milliseconds, I know the user has internet.
3. I try to ping intranet.company.org. If it returns Request timed out or Destination host unreachable, I know the problem lies in the path between the user and the intranet (perhaps a dropped VPN).

graph LR
    A[My Computer] -- Send Request (Echo Request) --> B[Target Server]
    B -- Response in 20ms (Echo Reply) --> A
    
    style A fill:#a2d2ff,stroke:#333
    style B fill:#ffc8dd,stroke:#333

2. Where did it get stuck? TRACERT (Traceroute)

While ping just says “I got there and back,” tracert shows you every intersection (router) where the packet stopped.

Think of it like tracking a package from an e-shop. If the package doesn’t arrive, tracert shows you exactly which warehouse it’s stuck in.

When I use it: When a user reports drops while working on a server in Australia. Tracert can reveal that the problem begins right on the second “hop” on their home router, which is totally overwhelmed, so the fault is not in the company’s infrastructure at all.

3. What is DNS (Domain Name System)

DNS translates domain names (e.g., google.com), which people understand, into IP addresses (e.g., 142.250.180.14), which computers understand.

It’s like a phone book. We know the name of the company, and DNS gives us the exact phone number to connect.

sequenceDiagram
    participant User
    participant DNS Server
    participant Target Server

    User->>DNS Server: Hey, what is the IP for intranet.company.org?
    DNS Server-->>User: Here it is: 192.168.1.15
    User->>Target Server: Connecting to 192.168.1.15!
    Target Server-->>User: Hello, welcome to the intranet.

When DNS breaks: A user can ping to 8.8.8.8 (Google) just fine, but when trying to ping google.com, they get a “host not found” error. Sometimes it is enough to just clear the memory of these “records” on the computer with the simple command ipconfig /flushdns and the problem is gone.

Knowing basic command-line commands like ping, tracert, and understanding the principle of DNS makes the difference between “handing over the task to networks (L2)” and “resolving it on the first call (First Call Resolution)”.