Use the traceroute command to diagnose IP routing problems

Use the traceroute command to diagnose IP routing problems. This command traces the route to a remote IP host and displays results. The traceroute command differs from ping in that traceroute shows where the route fails, while ping simply returns a single error on failure.

See the traceroute command description for command syntax and examples. The traceroute command has several parameters. Only host is required.

• host: The IP address of the destination host.
• bypass: Send directly to a host on an attached network.
• debug: Enable socket level debugging.
• dontfragment: Do not fragment probe packets.
• first_ttl: Specifies with what TTL to start. (Default: 1)
• gateway: Route the packet through a specified gateway.
• icmp: Use ICMP ECHO for probes.
• interface: Specifies the interface.
• ipchecksums: Calculate ip checksums.
• max_ttl: Specifies the maximum number of hops. (Default: 30)
• nomap: Do not map IP addresses to host names
• nqueries: Sets the number of probe packets per hop. (Default: 3)
• packetlen: Total size of the probing packet. (Default: -1)
• pausemsecs: Minimal time interval between probes (Default: 0)
• port: Specifies the destination port. (Default: -1)
• src_addr: Chooses an alternative source address.
• tos: Set Type of Service. (Default: -1)
• verbose: Verbose output.
• waittime: Max wait for a response to a probe. (Default: 5)

Example

This example shows using traceroute to verify that the IX14 device can route to host 8.8.8.8 (www.google.com) through the default gateway. The command output shows that 15 routing hops were required to reach the host:

1. Select the device in Remote Manager and click Actions > Open Console, or log into the IX14 local command line as a user with full Admin access rights.

   Depending on your device configuration, you may be presented with an Access selection menu. Type admin to access the Admin CLI.

2. At the Admin CLI prompt, use the traceroute command to view IP routing information:

   > traceroute 8.8.8.8
   traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 52 byte packets
    1  192.168.8.1 (192.168.8.1)  0 ms  0 ms  0 ms
    2  10.10.10.10 (10.10.10.10)  0 ms  2 ms  2 ms
    3  * 10.10.8.23 (10.10.8.23)  1 ms  1 ms
    4  96.34.84.22 (96.34.84.22)  1 ms  1 ms  1 ms
    5  96.34.81.190 (96.34.81.190)  2 ms  2 ms  2 ms
    6  * * *
    7  96.34.2.12 (96.34.2.12)  11 ms  11 ms  11 ms
    8  * * *
    9  8.8.8.8 (8.8.8.8)  11 ms  11 ms  11 ms
   >

By entering a whois command on a Unix device, the output shows that the route is as follows:

1. 192/8: The local network of the IX14 device.
2. 192.168.8.1: The local network gateway to the Internet.
3. 96/8: Charter Communications, the network provider.
4. 216/8: Google Inc.

Stop the traceroute process

To stop the traceroute process, enter Ctrl-C.