NAME

        Echo_Checksum.seq - check that sending and receiving Echo Request 
                            and Echo Reply (checksum)

TARGET

        Host/Router

SYNOPSIS

        Echo_Checksum.seq [-tooloption ...] -p Echo_Checksum.def

INITIALIZATION

        None

TEST PROCEDURE

        This test verifies that NUT receives valid ICMPv6 Echo Request 
        and sent ICMPv6 Echo Reply.

        TN                      NUT

        ---------------------------

        1.
         === ICMPv6 Echo Request ===>
                        src address : TN link local address
                        dst address : NUT link local address        
        2.
        << JUDGEMENT >>

         <=== ICMPv6 Echo Reply ===
                        src address : NUT link local address
                        dst address : TN link local address

JUDGEMENT

        << PASS >>
                Check Sum which is in a received packet is valid

        << FAIL >>      
                Check Sum which is in a received packet is invalid

REFERENCE

RFC2463 2.3 Message Checksum Calculation

   The checksum is the 16-bit one's complement of the one's complement
   sum of the entire ICMPv6 message starting with the ICMPv6 message
   type field, prepended with a "pseudo-header" of IPv6 header fields,
   as specified in [IPv6, section 8.1].  The Next Header value used in
   the pseudo-header is 58.  (NOTE: the inclusion of a pseudo-header in
   the ICMPv6 checksum is a change from IPv4; see [IPv6] for the
   rationale for this change.)

   For computing the checksum, the checksum field is set to zero.