TRACERT

Command

TRACERT -- Trace route to TCP/IP host.

Synopsis

TR[acert] <host> [maxhops [maxwait(ms)]]

Availability

All users.

Description

The TRACERT command is a diagnostic tool for displaying the route to an Internet Protocol host, and measuring the transit delays of packets at each step.

It uses the replies from a series of ICMP echo requests to produce a list of the routers that the packets have passed through.

3 attempts are made at each hop, thus for each hop, 3 round trip times are displayed, along with the IP address of the router at that hop. The 3 times indicate the consistency of the route. If no response is received within the timeout period, a "*" is displayed in the time field.

Options

<host> is the hostname or IP address of the target host.

[maxhops] is the maximum number of hops to trace (default 30).

[maxwait] is the maximum time to wait for a reply from each router. The default is 4 seconds.

The only required parameter is <host>. If the hostname doesn't contain at least one dot (.) the domain suffix specified in XROUTER.CFG (default .ampr.org.) is appended.

Entering TRACERT without any arguments displays a syntax reminder.

Examples

TR bbc.co.uk       - Trace bbc.co.uk with default parameters.
TR 44.141.91.2 10  - Trace 44.131.91.2 to a max of 10 hops.
TR g8pzt 5 20      - Trace g8pzt.ampr.org, 5 hops, max 20secs.

G8PZT-12:PZT12} Tracing route to g8pzt [44.131.91.4], max. 5 hops

1      0 ms     0 ms     0 ms   [44.131.91.246]
2      0 ms    55 ms    55 ms   [44.131.91.245]
3    165 ms    55 ms    55 ms   [44.131.91.4]

Trace complete.

Caveats

TRACERT relies on ICMP messages, and therefore requires that ICMP is correctly routed via front-end routers and firewalls etc. It will fail to produce a response from systems that are "stealthy" i.e. those that do not respond to ICMP. Such systems are indicated by "* * * Request timed out" lines.

The Traceroute function will not work unless XRPi has an IP address, and IP routing has been correctly set up.

See also

IP(1) -- IP Configuration Commands
PING(1) -- Send ICMP Echo request
STEALTH(9) -- TCP/IP Stealth Issues