Scenario

Users are reporting random timeouts. You need to determine whether packet loss occurs on the local network, upstream gateway, or public internet.

Task

Find your default gateway IP, ping the gateway, DNS server (8.8.8.8), and google.com (5 times each), collect packet loss and average latency from each, and write results to /tmp/network_diagnostics.txt showing target name, IP/hostname, packet loss percentage, and average latency.

Example

File: /tmp/network_diagnostics.txt

Gateway (192.168.1.1): loss=0% avg=1.2 ms
DNS (8.8.8.8): loss=0% avg=15.8 ms
Internet (google.com): loss=20% avg=83.5 ms

Step 1: Find your default gateway IP address

ip route | grep default | awk '{print $3}'

The command extracts your gateway IP from the routing table. Note this IP for the next steps.

Step 2: Ping the gateway, DNS server, and internet host

ping -c 5 YOUR_GATEWAY_IP
ping -c 5 8.8.8.8
ping -c 5 google.com

Replace YOUR_GATEWAY_IP with the IP from Step 1. The -c 5 flag sends 5 packets to test connectivity. From each ping output, note:

• Packet loss percentage (e.g., 0%)
• Average round-trip time (rtt avg value, e.g., 1.214 ms)

Testing in order (gateway → DNS → internet) follows the network path from local to global, helping identify where issues begin.

Step 3: Create the diagnostics file with your results

echo "Gateway (YOUR_GATEWAY_IP): loss=YOUR_LOSS% avg=YOUR_AVG ms" > /tmp/network_diagnostics.txt
echo "DNS (8.8.8.8): loss=YOUR_LOSS% avg=YOUR_AVG ms" >> /tmp/network_diagnostics.txt
echo "Internet (google.com): loss=YOUR_LOSS% avg=YOUR_AVG ms" >> /tmp/network_diagnostics.txt

Replace placeholders with actual values from the ping outputs. The > creates/overwrites the file, while >> appends without overwriting.

Step 4: Verify the file was created correctly

cat /tmp/network_diagnostics.txt