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Traceroute from FCR

The Traceroute tool helps you map the path that packets take from your Fabric Cloud Router (FCR) to a specified IP address. It’s a powerful way to:

  • Identify each hop along the route to a destination
  • Understand how traffic is routed through your network
  • Pinpoint where connectivity issues may be occurring

This tool is especially useful for diagnosing routing issues and visualizing the network path to a destination.

How to Use the Traceroute Tool​

  1. Go to the FCR Details page.
  2. Click the Network Tools tab.
  3. Select Traceroute from the left-hand menu.

Configure Your Traceroute Test​

  • Connection - Choose the connection you want to use as the source for the Traceroute test.

    note

    IP-WAN connections are not supported as a source.

  • Source IP Address - Select the IP address (IPv4 or IPv6) configured in the routing protocol for the chosen connection.

  • Destination IP Address - Enter the IP address you want to trace. Make sure it matches the IP version (IPv4 or IPv6) of the selected source.

Click the Traceroute button to start the test.

Traceroute sends two probes per hop, with a 1-second interval between probes, to map the path to the destination.

Example Traceroute Results​

Traceroute Initiated  
From DC-FCR-001 to 10.83.0.2  
June 13, 2025 16:04 UTC

traceroute to 10.83.0.2 (10.83.0.2), 20 hops max, 104 byte packets
 1  **** (****)           0.900 ms  0.971 ms  0.736 ms
 2  10.83.0.1 (10.83.0.1) 0.586 ms  0.602 ms  0.823 ms
 3  10.83.0.2 (10.83.0.2) 0.788 ms  0.905 ms  0.869 ms

Understanding Traceroute Results​

Each hop in the path is displayed with:

  • Hop Number
  • IP Address of the responding router
  • Round-trip time for each of the two probes (in milliseconds)
  • Asterisks (*) indicate no response received for that probe
note

Some routers may not respond to traceroute probes or may deprioritize them. This can result in missing hops or misleading latency values. Traceroute is best used to understand the path, not to measure performance at each hop.

What If the Traceroute Fails?​

ResultWhat It Means
* * for all hopsNo responses received. The destination or intermediate routers may be blocking ICMP or UDP probes.
Partial pathSome hops responded, but the trace didn’t complete. This may indicate filtering or a routing issue.
No route to hostThe FCR doesn’t have a valid route to the destination. Check routing settings.
TTL expiredPackets exceeded the maximum hop limit without reaching the destination. May indicate a loop or unreachable path.
tip

If some hops show asterisks but the trace completes, it may be due to firewalls or routers configured to ignore traceroute probes.

When to Use the Traceroute Tool​

Diagnose Routing Issues

  • Identify where traffic is being dropped or rerouted
  • Detect routing loops or unreachable segments

Understand Network Paths

  • Visualize the route traffic takes from your FCR to a destination
  • Confirm expected routing behavior across your network

Complement Other Tools

  • Use alongside Ping to correlate end-to-end connectivity with path-level visibility
  • Help isolate where in the network a failure or misconfiguration may be occurring