traceroute

Sends three probe packets to trace the routers in the path to a specified destination. For each router in the path, the hostname and IP address are shown, along with the roundtrip times measured for each probe.

Syntax

traceroute [-46dFITnreAUDV] [-f first_ttl] [-g <gate>,...] [-i <device>] [-m max_ttl] [ -N <squeries>] [-p <port>] [-t <tos>] [-l <flow_label>] [-w <waittime>] [-q nqueries>] [-s <src_addr><] [-z <sendwait>] [--fwmark=num] host [<packetlen>]

Parameters

-4

Use IPv4.

-6

Use IPv6.

-d --debug

Enable socket level debugging.

-F --dont-fragment

Do not fragment packets.

-f first_ttl --first=first_ttl

Start from the first_ttl hop (instead from 1).

-g gate,... --gateway=gate,...

Route packets through the specified gateway (maximum 8 for IPv4 and 127 for IPv6).

-I --icmp

Use ICMP ECHO for tracerouting.

-T --tcp

Use TCP SYN for tracerouting (default port is 80).

-i device --interface=device

Specify a network interface to operate with.

-m max_ttl --max-hops=max_ttl

Set the max number of hops (max TTL to be reached). Default is 30.

-N squeries --sim-queries=squeries

Set the number of probes to be tried simultaneously (default is 16).

-n

Do not resolve IP addresses to their domain names.

-p port --port=port

Set the destination port to use. It is either the initial udp port value for "default" method (incremented by each probe, default is 33434), or initial seq for "icmp" (incremented as well, default from 1), or some constant destination port for other methods (with default of 80 for "tcp", 53 for "udp", and so on).

-t tos --tos=tos

Set the TOS (IPv4 type of service) or TC (IPv6 traffic class) value for outgoing packets.

-l flow_label --flowlabel=flow_label

Use the specified flow label for IPv6 packets.

-w waittime --wait=waittime

Set the number of seconds to wait for response to a probe (default is 5.0). Non-integer (floating point) values are allowed.

-q nqueries --queries=nqueries

Set the number of probes per each hop. Default is 3.

-r

Bypass the normal routing and send directly to a host on an attached network.

-s src_addr --source=src_addr

Use the source address for outgoing packets.

-z sendwait --sendwait=sendwait

Minimum time interval between probes (default 0). If the value is more than 10, then it specifies a number in milliseconds, else it is the number of seconds (floating point values are allowed).

-e --extensions

Show ICMP extensions (if present), including MPLS.

-A --as-path-lookup

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

-M name --module=name

Use the specified module (either builtin or external) for traceroute operations. Most methods have their shortcuts (for example, `-I' means `-M icmp').

-O OPTS,... --options=OPTS,...

Use module-specific option OPTS for the traceroute module. Several OPTS are allowed, separated by commas. If OPTS is "help", print information about available options.

--sport=num

Use source port num for outgoing packets. Implies `-N 1'.

--fwmark=num

Set firewall mark for outgoing packets.

-U --udp

Use UDP to a particular port for tracerouting (instead of increasing the port per each probe). The default port is 53.

-UL

Use UDPLITE for tracerouting. The default dest port is 53.

-D --dccp

Use DCCP Request for tracerouting. The default port is 33434.

-P prot --protocol=prot

Use raw packet of protocol prot for tracerouting.

--mtu

Discover MTU along the path being traced. Implies `-F -N 1'.

--back

Guess the number of hops in the backward path and print if it differs.

-V --version

Print version information and exit.

--help

Print this help and exit.

Arguments:

+ host

The host to traceroute to.

packetlen

The full packet length (default is the length of an IP header plus 40). Can be ignored or increased to a minimal allowed value

Example

The following example traces the path to the specified address, and omits hostname lookups for the output.

hostname > traceroute -n 192.168.0.127
traceroute to 192.168.0.127 (192.168.0.127), 30 hops max, 40 byte packets
1 192.168.53.130 2 ms 0 ms 0 ms
2 192.168.53.70 2 ms 2 ms 4 ms
3 192.168.53.1 0 ms 2 ms 2 ms
4 192.168.52.15 2 ms 2 ms 2 ms
5 192.168.0.127 2 ms 2 ms 2 ms

Supported appliances