NETTEST(8N)             COMMAND REFERENCE             NETTEST(8N)



NAME
     nettest - network diagnostic test utility

SYNOPSIS
     /etc/nettest [ -p proto ] [ -r node [ paddr ] ] [ -t
     interface ] [ count ]

DESCRIPTION
     The nettest command provides the user with the capability to
     conduct a loopback test of the local host's network
     functions and to perform a time domain reflectometry (TDR)
     check of a network medium.

     The loopback test allows the user to verify the operation of
     the networking software and hardware.  Also, the user can
     test the data link between the local host and a selected
     remote host.  Normally, this test sends its test data to an
     ``echo server'' via the datagram (UDP) protocol and waits
     for a reply.  The data, if returned, are compared to the
     original data to determine if any transmission errors
     occurred.

     Alternatively, the user may elect to use the stream (TCP) or
     control message (ICMP) protocols for data transmission.  The
     ICMP protocol handles the echoing of data directly, so no
     echo server is required in this case.

     Faults in a physical medium may be located through use of
     the LAN chip set's inherent TDR capability.  Time domain
     reflectometry is a technique for locating discontinuities in
     a transmission line by injecting a signal into the cable and
     measuring the time interval between the incident signal and
     any reflection of that signal caused by an open or short in
     the transmission cable.  In the LAN environment, signal
     reflections result in collisions, and since the point of the
     open or short is fixed, the time to collision is constant.
     Thus, it is possible to gauge the approximate distance to
     the cable fault by asserting the carrier signal and
     measuring the time until a collision occurs.  In the case of
     the LAN chip set in use, the approximation is accurate to
     within 11.7 meters (≅ 38.4 feet), depending upon the LAN
     configuration in use.

     If an iteration count is specified, nettest displays a ``+''
     for each successful packet loopback, a ``?'' for each
     missing packet, and a ``-'' for each incorrect packet (e.g.,
     CRC error, alignment error, or bad comparison).  If the
     iteration count is specified for a TDR test, nettest reports
     the total number and type of each fault which may have
     occurred.





Printed 10/17/86                                                1

NETTEST(8N)             COMMAND REFERENCE             NETTEST(8N)



OPTIONS
     -p proto
         Use protocol proto when performing the loopback test.
         Proto may be TCP, UDP (default), or ICMP.

     -r node
         Perform loopback test via the specified remote node.
         Node may be an explicit host name as specified in the
         /etc/hosts database, or it may be an Internet address
         written in ``.'' notation.

     -r node paddr
         Perform loopback test via the specified remote node at
         physical address paddr. The physical address is written
         as six hex bytes separated by colons (e.g.,
         08:00:11:00:8c:22).  Typically, this form is used to
         direct the loopback to a newly-installed or otherwise
         unknown node, in which case node is specified as an
         Internet address in order to update the information in
         the ARP tables.

     -t interface
         Perform a TDR test of the network physical medium via
         the network interface named interface. (Interface names
         and network numbers may be found by using the netstat
         utility.)

     count
         Perform the specified test count times.

EXAMPLES
     nettest -t lna0
         Perform a TDR test of the network physical medium
         attached to network interface ``lna0''.

     nettest -p icmp -r 8.10.21.234 00:01:02:03:04:05
         Perform a loopback test via the remote host at physical
         address ``0 1 2 3 4 5'' using the Internet Control
         Message Protocol (ICMP).

FILES
     /etc/hosts               Data base for host names and
                              addresses.

DIAGNOSTICS
     Nettest displays error messages describing any system or
     data errors which might occur.

RETURN VALUE
     [0]            The test passed.

     [1]            The test failed.



Printed 10/17/86                                                2

NETTEST(8N)             COMMAND REFERENCE             NETTEST(8N)



     [USAGE]        Incorrect command line syntax. Execution
                    terminated.

     [NP_ERR]       An error occurred that was not a system
                    error.  Execution terminated.

     [P_ERR]        A system error occurred. Execution
                    terminated.  See intro(2) for more
                    information on system errors.

CAVEATS
     Use of the UDP or TCP protocols during the loopback test
     requires that an echo server (see udpd(8n) and tcpd(8n)) be
     running on the target node in order for the test to pass.

     During the TDR test, hardware anomalies may cause some hosts
     to falsely identify faults in the network medium when none
     actually exist.  Therefore, confirm any indicated faults
     either by performing the nettest TDR on at least one other
     host on the network or by testing the network medium with a
     TDR cable tester.

     Since raw sockets are privileged, only the super-user may
     use the ICMP loopback test.

     Since entry of address information into the ARP tables is a
     restricted operation, only the super-user may specify the
     Internet and physical address of an unknown node.

SEE ALSO
     netstat(1n), sh(1sh), inet(3n), syslog(3c), arp(4n),
     hosts(5n), arp(8n), tcpd(8n), udpd(8n).























Printed 10/17/86                                                3

%%index%%
na:72,77;
sy:149,307;
de:456,2443;
op:3043,1416;
ex:4459,421;
fi:4880,153;
di:5033,219;
rv:5252,154;5550,378;
ca:5928,933;
se:6861,288;
%%index%%000000000169