Quick Answer

Traceroute shows each network hop between you and a destination. Each line displays: hop number, router hostname/IP, and three latency measurements in milliseconds. Look for where latency suddenly increases - that's likely where the problem is. Asterisks (*) mean the router didn't respond, which is often normal for security reasons. Use ProbeOps Multi-Region Traceroute at probeops.com/tools/traceroute to compare paths from different locations.

When to Use Traceroute

• Diagnosing slow website or application performance
• Identifying where packet loss is occurring on a network path
• Troubleshooting connectivity issues to a specific server
• Verifying traffic is routing through expected networks
• Investigating intermittent connection problems

Understanding Traceroute Output

Step 1: Identify Each Hop

Each numbered line represents a router or network device. Hop 1 is usually your local router. Subsequent hops show the path through ISP networks, internet exchanges, and finally the destination's network.

Step 2: Analyze Latency Values

Each hop shows three time measurements in milliseconds. These are three separate probes. Consistent times indicate stable performance. Wide variation suggests network congestion or an unstable connection.

Step 3: Identify Latency Spikes

Compare latency between consecutive hops. A jump from 20ms to 150ms indicates the connection between those two routers is slow. Geographic distance naturally adds latency (cross-ocean links add 60-100ms).

Step 4: Interpret Timeouts and Asterisks

Asterisks (*) mean the router didn't respond to the probe. This is often normal - many routers are configured to ignore traceroute packets for security. If the final destination responds, intermediate timeouts are usually not a problem.

Step 5: Check the Final Hop

The last hop should be your destination. If traceroute never reaches the destination and shows only asterisks, there may be a firewall blocking traffic or a routing problem.

Example: Reading Traceroute Output

Input

Destination: google.com

Output Analysis

Hop 1: 192.168.1.1 (1ms, 1ms, 1ms) - Local router, excellent latency. Hop 2: 10.0.0.1 (10ms, 12ms, 11ms) - ISP first hop, normal. Hop 3: isp-router.example.net (15ms, 14ms, 16ms) - ISP backbone, stable. Hop 4: * * * - Router not responding, normal. Hop 5: google-peer.example.net (25ms, 24ms, 26ms) - Peering point. Hop 6: 142.250.x.x (26ms, 25ms, 27ms) - Google's network, destination reached.

Common Traceroute Patterns

Pattern: High latency at one hop, normal after

The router is slow to respond to ICMP but forwards traffic normally. This is a router issue, not a path issue. Ignore if subsequent hops are fine.

Pattern: Latency increases and stays high

Indicates a congested or distant link. All subsequent hops will show higher latency because it's cumulative. The problem is at the hop where the jump occurred.

Pattern: All asterisks after a certain hop

Either a firewall is blocking traceroute packets or routing has failed. Try using TCP mode instead of ICMP. If the destination is reachable via HTTP, the firewall is likely blocking traceroute specifically.

Related Tools

• Multi-Region Traceroute - Trace paths from 6 global locations
• Latency Test - Measure round-trip time and TTFB
• Is It Down Checker - Verify if destination is reachable