NAME

        setMTUwithRA - Verify changing MTU w/ received RA


TARGET

        Host


SYNOPSIS

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


NETWORK CONFIGURATION

        This test evaluate the behavior of NUT when it receive the RA
        with MTU option.
        In this test, NUT is a host and TN plays a Roll of Router and 
        other host.
        
        Phisical Network configuration
        
        --------+---------------+----------
                |               |
                NUT             TN

        Logical Network Configuration

                                NUT
                                |
        ----------------+-------+--------
                        |
                        Router-A
                        |
        ----------------+-------+--------
                                | 
                                HOST

        In this test, NUT receives RA with MTU.


INITIALIZATION

        The TN send a RA to assign global address prefix.

           TN          NUT
           |            |
        ---+------------+------

        ===multicast RA===>
        src=TN's link-local
        dst=LinkLocal-all-node                   
        M=0, O=0,
        Lifetime=3600, ReachableTime=60000, RetransTimer=1005
        Prefix:
           L=1, A=1,                       
           ValidLifetime=3600005, PreferredLifetime=3600005
           Prefix=3ffe:501:ffff:100::, PrefixLength=64                      
        option
           MTU=1400
   
          Wait (5 sec.)
                 Ignoring DAD packets for global address.                 


TEST PROCEDURE

        "setMTUwithRA" verify NUT's behavior when it receives RA with MTU option.

           TN          NUT
           |            |
        ---+------------+------

        1. RA (MTU=1400)
        TN send RA with MTU=1400.
        TN === RA(MTU=1400) ===> NUT

        2. TN Sends Fragmented Echo Request
        TN send Echo Request.  
        TN ==== echo request(1400) ===> NUT

        4. NUT Sends Fragmented Echo Reply
        NUT send Echo Reply.
        << JUDGMENT 1 >>
        TN <=== echo reply(1400) ====== NUT

        3. TN Sends Fragmented Echo Request
        TN send Echo Request.  
        TN === echo request(1/2 of 1500 MTU=1400) ===> NUT
        TN === echo request(2/2 of 1500 MTU=1400) ===> NUT

        4. NUT Sends Fragmented Echo Reply
        NUT send Echo Reply 
        << JUDGMENT 1 >>
        TN <=== echo reply(1/2 of 1500 MTU=1400) === NUT
        TN <=== echo reply(2/2 of 1500 MTU=1400) === NUT


JUDGMENT

        << JUDGMENT 1 -PASS- >>
                NUT sends Echo Reply

                "PASS" means that NUT set valid MTU in received RA.
                And fragmented packets are correct.
                But if the NUT doesn't support PMTU Discovery, the NUT MUST NOT send echo reply greater than Minimum MTU.

        << JUDGMENT 2 -PASS- >>
                NUT sends Echo Reply

                "PASS" means that NUT sets valid MTU in received RA.
                And fragmented packets are correct.
                But if the NUT is LCNA, it may not be able to deal with packets greater than Minimum MTU, in this case NUT doesn't transmit echo reply. And also it could not fragment packets, in this case NUT doesn't transmit echo reply. Both cases are allowed in LCNA specification.


SEE ALSO

        perldoc V6evalTool
        perldoc V6evalRemote