traceroute

Print the route packets take to network host.

Syntax
      traceroute [options] host [packetsize]

Options:

   -I    Use ICMP ECHO for probes 
   -T    Use TCP SYN for probes 
   -U    Use UDP datagrams for probes (default). Only UDP is allowed for unprivileged users. 
   -d    Enable socket level debugging (when the Linux kernel supports it) 

   -F    Set the "Don't Fragment" bit. This tells intermediate routers not to fragment
         the packet when they find it's too big for a network hop's MTU. 

   -f first_ttl
         With what TTL to start. Default = 1 

   -g gateway
         Adds an IP source route gateway to the outgoing packet. Not useful, as
         most routers have disabled this for security reasons. 

   -i interface
         The interface through which traceroute should send packets.
         Default = select according to the routing table. 

   -m max_ttl
         The max no. of hops (max time-to-live value) traceroute will probe. Default=30 hops

   -N squeries
         The number of probe packets sent out simultaneously. Sending several probes
         concurrently can speed up traceroute considerably. Default = 16
         Note that some routers and hosts can use ICMP rate throttling. In such a situation
         specifying too large number can lead to loss of some responses. 

   -n    Show numerical addresses; do not look up hostnames.
         (Useful if DNS is not functioning properly.)

   -p port
         For UDP tracing: the destination port base traceroute will use
         (the destination port number will be incremented by each probe).
         For ICMP tracing: the initial icmp sequence value (incremented by each probe).
         For TCP tracing: the (constant) destination port to connect. 
   -t tos
         For IPv4, set the Type of Service (TOS) and Precedence value.
         Useful values are 16 (low delay) and 8 (high throughput).
         Note that in order to use some TOS precendence values, you have to be super user.
         For IPv6, set the Traffic Control value. 

   -w waittime
         Set the time (in seconds) to wait for a response to a probe (default 5.0 sec). 

   -q nqueries
         Set the number of probe packets per hop. Default = 3 

   -r    Bypass the normal routing tables and send directly to a host on an attached network.
         If the host is not on a directly-attached network, an error is returned.
         This option can be used to ping a local host through an interface that has no route through it. 

   -s source_addr
         Choose an alternative source address. You must select the address of one of the interfaces.
         Default = address of the outgoing interface. 

   -z sendwait
         Minimal time interval between probes (default 0). If the value is more than 10,
         then it specifies a number in milliseconds, else it is a number of seconds
        (float point values allowed too). Useful when some routers use rate-limit for icmp messages. 

   -A    Perform AS path lookups in routing registries and print results directly after
         the corresponding addresses 

   -V    Print the version and exit.

   --help  Print help info and exit. 

   -4, -6  Explicitly force IPv4 or IPv6 traceouting. By default, the program will try
           to resolve the name given, and choose the appropriate protocol automatically.
           If resolving a host name returns both IPv4 and IPv6 addresses, traceroute will use IPv4. 

"The Net interprets censorship as damage and routes around it" - John Gilmore

Related Linux Bash commands:

netstat(1)
ping(8)
route - manipulate routing tables

Equivalent Windows XP commands:

tracert - Trace Route