How to Read Traceroute Results Like a Pro

Traceroute is one of the most useful networking diagnostic tools available, yet most people have no idea how to interpret its output. Those rows of numbers, hostnames, and asterisks tell a detailed story about the path your data takes from your device to its destination — and where problems might be occurring.

Whether you are troubleshooting slow websites, diagnosing packet loss, or just curious about how the internet works, learning to read traceroute results is a valuable skill. You can run a traceroute right now using our Traceroute tool.

What Traceroute Actually Does

Traceroute works by sending packets with incrementally increasing TTL (Time to Live) values. TTL is a counter that decreases by 1 at each router (hop) along the path. When a packet's TTL reaches 0, the router discards it and sends back an ICMP "Time Exceeded" message.

Here is the process:

1. Send a packet with TTL=1 → the first router decrements to 0, sends back a response with its IP
2. Send a packet with TTL=2 → passes the first router, the second router responds
3. Send a packet with TTL=3 → passes two routers, the third responds
4. Continue until the destination is reached or the maximum hop count is hit

Each round of packets (usually three per hop) measures the round-trip time (RTT) to that specific router.

Anatomy of a Traceroute Result

Here is a typical traceroute output:

 1  192.168.1.1      1.234 ms   0.987 ms   1.102 ms
 2  10.0.0.1         8.432 ms   7.891 ms   8.210 ms
 3  isp-gw.example.net  12.345 ms  11.987 ms  12.102 ms
 4  core-rtr.isp.com    15.678 ms  14.321 ms  15.012 ms
 5  ix-peer.exchange.net 22.456 ms  21.789 ms  22.134 ms
 6  cdn-edge.target.com  25.123 ms  24.567 ms  25.890 ms

Each line represents one hop — a router or network device your packet passed through. Let us break down what each column means:

Column 1: Hop Number

The sequential number of the router in the path. Hop 1 is usually your home router, and the last hop is the destination.

Column 2: Hostname or IP Address

The identity of the router at that hop. If DNS reverse lookup succeeds, you see a hostname (like isp-gw.example.net). Otherwise, you see a raw IP address. You can look up any of these IPs using our IP Lookup tool to find out who owns them and where they are located.

Columns 3-5: Round-Trip Time (RTT)

Three time measurements in milliseconds (ms), one for each probe packet sent to that hop. These tell you how long it takes for a packet to travel to that router and back.

How to Interpret RTT Values

Normal Latency Patterns

Latency should generally increase gradually as you move further from your device:

• Hop 1 (your router): 1-5 ms — this should be very fast
• Hops 2-3 (ISP network): 5-20 ms — your traffic within your ISP's infrastructure
• Hops 4-6 (backbone/peering): 15-50 ms — internet backbone and exchange points
• Final hop (destination): varies by distance — same continent is 20-80 ms, cross-ocean can be 100-200+ ms

What the Numbers Tell You

Consistent low RTT across all three probes (e.g., 15.2, 14.8, 15.1):

The connection to this hop is stable and healthy.

One probe significantly higher than the others (e.g., 15.2, 14.8, 89.3):

This is usually not a problem. Routers prioritize forwarding real traffic over responding to ICMP packets. An occasional slow response does not indicate a real issue.

All three probes high at one hop but normal at the next (e.g., Hop 4: 120ms, Hop 5: 25ms):

The router at hop 4 is slow to respond to ICMP but is actually forwarding traffic normally. This is very common with busy core routers and is not a problem.

All probes high starting at a specific hop and staying high for all subsequent hops:

This indicates a genuine bottleneck. The router where latency jumps is likely the problem (or the link between it and the previous hop). Everything downstream inherits that latency.

Example of a real bottleneck:

 3  isp-gw.example.net   12.3 ms  11.9 ms  12.1 ms
 4  congested-rtr.isp.com 85.6 ms  92.3 ms  88.1 ms   ← latency jump
 5  peer.transit.net      87.2 ms  89.5 ms  86.8 ms   ← stays high
 6  destination.com       90.1 ms  91.7 ms  89.3 ms   ← stays high

The problem is at or between hops 3 and 4. Everything after inherits the delay.

Understanding Asterisks and Timeouts

 4  * * *

Three asterisks mean no response was received from that hop. This does not necessarily mean there is a problem. Many routers are configured to drop ICMP packets (for security or performance), so they simply do not respond to traceroute probes.

When asterisks are normal:

• A single hop with * followed by normal hops — the router just does not respond to ICMP
• Firewall-protected network segments often show as timeouts

When asterisks indicate a problem:

• Multiple consecutive * hops at the end of the trace — your packets are not reaching the destination
• The trace never completes and times out — the destination or its network may be down

Reading Hostnames for Clues

The hostnames of routers often encode useful information:

• Geographic codes: lax (Los Angeles), ams (Amsterdam), nrt (Tokyo Narita), lhr (London Heathrow)
• Router roles: gw (gateway), core (core router), edge (edge/border router), ix (internet exchange)
• ISP names: comcast, att, level3, telia — tells you whose network you are traversing
• Interface types: ge (gigabit ethernet), xe (10-gigabit), ae (aggregated ethernet)

For example, ae1.cr2.lax1.us.nlayer.net tells you this is an aggregated ethernet interface on core router 2 in Los Angeles, on NLayer's US network.

Use our ASN Lookup tool to identify which organization owns each network segment in the trace.

Common Traceroute Scenarios

Scenario 1: Slow First Hop

 1  192.168.1.1   45.2 ms  52.1 ms  48.7 ms

Your home router is slow. Possible causes: router overloaded, Wi-Fi interference, or outdated firmware. Try connecting via Ethernet to isolate the issue.

Scenario 2: Latency Spike at ISP

 2  10.0.0.1       8.4 ms   7.9 ms   8.2 ms
 3  isp-gw.net    85.6 ms  92.3 ms  88.1 ms

Congestion on your ISP's network. Common during peak hours. Run a Speed Test to confirm if bandwidth is affected.

Scenario 3: Packet Loss at a Specific Hop

 5  problem-rtr.net  45.2 ms  *  46.1 ms

One of three probes timed out. If this pattern is consistent across multiple traceroutes, there may be intermittent packet loss at that router.

Scenario 4: Route Change Mid-Trace

Running traceroute multiple times may show different paths. This is normal — internet routing is dynamic, and load balancing across multiple paths is standard practice.

Scenario 5: Traceroute Ends Early

 8  border-rtr.host.com  35.2 ms  34.8 ms  35.1 ms
 9  * * *
10  * * *

The destination's network is likely blocking ICMP. This does not necessarily mean the site is down — try accessing it in a browser.

How to Run Traceroute

Using Our Online Tool

The easiest method is our web-based Traceroute tool. Enter any domain or IP and get results instantly without installing anything.

Command Line

Windows:

tracert example.com

macOS / Linux:

traceroute example.com

Advanced options:

• traceroute -n example.com — skip DNS lookups (faster results)
• traceroute -q 5 example.com — send 5 probes per hop instead of 3
• traceroute -T example.com — use TCP instead of UDP (bypasses some firewalls)

Traceroute vs Ping

Both tools measure latency, but they serve different purposes:

• Ping tells you if a destination is reachable and how long it takes — it is a single end-to-end measurement
• Traceroute shows you every step of the journey, revealing where problems occur

Use ping for a quick "is it up?" check. Use traceroute when you need to diagnose where the problem is. Use both with our Ping and Traceroute tools.

Tips for Accurate Traceroute Analysis

1. Run it multiple times — a single traceroute is a snapshot. Run 3-5 at different times to see patterns.
2. Compare paths — run traceroute from different devices or networks to determine if the issue is local or widespread.
3. Focus on sustained latency increases — a jump at one hop that carries through to all subsequent hops is meaningful. A spike at one hop that recovers at the next is usually harmless.
4. Do not panic about asterisks — they are more often security policy than actual problems.
5. Use the right tool — for cross-ocean traces, high latency is physics, not a problem. Light takes about 70ms to cross the Atlantic.

Conclusion

Traceroute transforms abstract network problems into visible, diagnosable paths. Once you know how to read the hops, RTT values, and patterns, you can quickly identify whether a slow connection is caused by your local network, your ISP, a peering point, or the destination itself.

Bookmark our Traceroute tool and use it alongside DNS Lookup and IP Lookup for a complete network diagnostic toolkit.