NAME

        rfc2765_4.1_payloadlength.seq - Verify IPv6 <-> IPv4 header 
        translation in accordance with RFC2765 [SIIT]

TARGET

        Router

INITIALIZATION

	Before this test starts, run initialize.seq.

TEST PROCEDURE

        This test verifies that NUT can translates IPv4 header
        to IPv4 header, when IPv6 header contain options.
        
        Network Topology

        Link0
        --------------------------
            |               |
           TN              NUT
            |               |
        --------------------------
        Link1

        TN -- (Link0) -- NUT        NUT -- (Link1) -- TN
        
        ---------------------      ------------------------

        1.1.
        ===================>
        ICMPv6 Echo Request
                IPv6 Header
                        src address : TN LINK0 IPv4 embedded IPv6 address
                        dst address : TN LINK1 IPv4 embedded IPv6 address
                Destination options header
                ICMPv6 echo request
         
        1.2.
        <<JUDGMENT>>
                                   ===================>
        ICMPv4 Echo request
                IPv4 Header
                        src address : TN LINK0 IPv4 address
                        dst address : TN LINK1 IPv4 address
                        Don't Fragment = 1
                        MF = 0
                        FragmentOffset = 0
                        TotalLength = 34
                        Identifier = 0
                ICMPv4 echo request

JUDGMENT

        << PASS >>
                TN (Link1) an ICMPv4 Echo request.
                with correct total length.
                
        << FAIL >>      
                TN (Link1) receive an ICMPv4 echo requests, 
                with payload length 8 bytes too large.

NOTE

REFERENCE

RFC2765

4.1. Translating IPv6 Headers into IPv4 Headers

   If there is no IPv6 Fragment header the IPv4 header fields are set as
   follows:

         Total Length:
                 Payload length value from IPv6 header, plus the size
                 of the IPv4 header.

         Identification:
                 All zero.

         Flags:
                 The More Fragments flag is set to zero.  The Don't
                 Fragments flag is set to one.

         Fragment Offset:
                 All zero.