Traceroute is a network diagnostic tool that discovers the path packets take from your computer to a destination on the Internet.
Unlike Ping, which only answers:
“Can I reach the destination?”
Traceroute answers:
“How do I reach the destination?”
It identifies each router (called a hop) along the path.
Traceroute helps diagnose problems such as:
It is one of the most useful tools for troubleshooting Internet connectivity.
Traceroute sends packets with gradually increasing Time To Live (TTL) values.
Example:
TTL = 1 ↓ Router 1 ↓ ICMP Time Exceeded
Then:
TTL = 2 ↓ Router 1 ↓ Router 2 ↓ ICMP Time Exceeded
Then:
TTL = 3 ↓ Router 1 ↓ Router 2 ↓ Router 3 ↓ ICMP Time Exceeded
This continues until the destination responds.
Each router reveals its address by sending an ICMP Time Exceeded message.
A typical traceroute might look like:
1 192.168.1.1 2 10.25.0.1 3 185.229.29.1 4 172.217.20.46
Each line represents one hop.
The final hop is usually the destination.
A hop is one router that forwards your packet.
Example:
Your Computer
│
Hop 1
Home Router
│
Hop 2
ISP Router
│
Hop 3
Regional Router
│
Hop 4
Destination
The number of hops depends on the network path.
Traceroute usually measures the response time for each hop.
Example:
Hop RTT 1 1 ms 2 8 ms 3 21 ms 4 22 ms
A sudden increase may indicate:
Many traceroute implementations send three probes for each hop.
Example:
5 24 ms 25 ms 23 ms
Multiple probes help identify:
Sometimes a hop is displayed as:
7 * * *
This usually means the router did not reply.
Possible reasons include:
A missing reply does not necessarily mean the router is broken.
If later hops respond normally, the router is still forwarding traffic.
| Ping | Traceroute |
|---|---|
| Tests reachability | Discovers the network path |
| Reports overall latency | Reports latency at each hop |
| Uses ICMP Echo | Uses increasing TTL values |
| Does not identify routers | Shows intermediate routers |
These tools complement each other.
Different operating systems use different probe types.
| Operating System | Typical Probe Type |
|---|---|
| Windows (tracert) | ICMP Echo Request |
| Linux (traceroute) | UDP (default) |
| Linux (optional) | ICMP or TCP |
| macOS | UDP (default) |
Although the probe types differ, the principle remains the same.
Telenegar Trace Route performs traceroute from multiple probe locations.
This allows you to compare routing from different ISPs and regions.
For each probe, Telenegar may report:
This makes it easier to determine whether a routing problem is:
Suppose users report that a website is slow.
Ping shows:
Destination reachable RTT = 120 ms
Traceroute shows:
Hop 1 1 ms Hop 2 6 ms Hop 3 9 ms Hop 4 110 ms Hop 5 112 ms
This suggests that the delay begins near Hop 4, helping identify where the problem occurs.