… Tracing...

About Traceroute

Traceroute is a program that tracks the path of data between two points. In this case, it tracks the path of data from our server, to your computer. This can be a great way to analyze your internet connection to find out if there is a problem somewhere.

This program attempts to trace the route an IP packet would follow to some internet host by launching UDP probe packets with a small ttl (time to live) then listening for an ICMP "time exceeded" reply from a gateway. We start our probes with a ttl of one and increase by one until we get an ICMP "port unreachable" (which means we got to "host") or hit a max. Three probes are sent at each ttl setting and a line is printed showing the ttl, address of the gateway and round trip time of each probe. If the probe answers come from different gateways, the address of each responding system will be printed. If there is no response within a 2 second timeout interval, a "*" is printed for that probe.

Additional annotations:

  • !  - TTL <= 1
  • !H - host unreachable
  • !N - network unreachable
  • !P - protocol unreachable
  • !S - source route failed
  • !U - destination network unknown
  • !W - host unknown
  • !I - source host is isolated
  • !A - communication with destination network administratively prohibited
  • !Z - communication with destination host administratively prohibited
  • !Q - for this ToS the destination network is unreachable
  • !T - for this ToS the destination host is unreachable
  • !X - communication administratively prohibited
  • !V - host precedence violation
  • !C - precedence cutoff in effect
  • !# - ICMP unreachable code #