How to Troubleshoot Network Problems With Ping, Traceroute and MTR

Step by step

1. Start from the inside out

   Test in this order: your own gateway, a server in the same building, a server at another site, then an Internet address. The first test that fails tells you which part of the network to look at.

   ping -c 20 10.1.10.1      # default gateway
   ping -c 20 10.1.20.15     # local server
   ping -c 20 10.2.10.1      # remote site gateway
   ping -c 20 1.1.1.1        # Internet
   

2. Read loss and latency, not just 'reply'

   Look at the summary line. On a wired LAN, expect 0% loss and under 1 ms. Over Wi-Fi expect 1–5 ms. Loss of 1% or more, or jitter (big differences between min and max), points to a problem even when the ping 'works'.

   --- 10.1.20.15 ping statistics ---
   20 packets transmitted, 20 received, 0% packet loss
   rtt min/avg/max/mdev = 0.312/0.401/0.622/0.071 ms
   

3. Follow the path with traceroute

   Traceroute lists every router between you and the target. -n skips name lookups so it runs faster. On Windows the command is tracert -d.

   traceroute -n 10.2.30.40
   # Windows:
   tracert -d 10.2.30.40
   

4. Use MTR for the full picture

   MTR repeats traceroute continuously and shows loss and latency for each hop. Run at least 100 cycles in report mode and save the output for your ticket or ISP.

   mtr -rwzbc 100 10.2.30.40
   # -r report  -w wide  -z AS numbers  -b names+IPs  -c 100 cycles
   

5. Read the MTR report correctly

   Loss that appears on one hop but NOT on the hops after it is usually only that router limiting ICMP replies: ignore it. Loss that starts at one hop and continues to the final destination is real, and it begins at that hop or the link just before it.

6. Test with the real protocol

   Some firewalls block ICMP but allow the application. Test the actual TCP port so you know whether the service itself answers.

   nc -vz 10.2.30.40 443
   # Windows PowerShell:
   Test-NetConnection 10.2.30.40 -Port 443
   

7. Write down what you found

   Record the time, source, destination, loss % and the hop where problems start. That turns 'the network is slow' into a fault you can fix or send to the ISP.

Commands are generic, industry-standard examples. Exact syntax and menu names vary by model and firmware; check your device's manual on the Documentation page.