NAME

        checkPMTUincrease - Verify that node detects increase Path MTU

TARGET

        Host

SYNOPSIS

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

NETWORK CONFIGURATION

        This test is OFF-LINK Network Configuration test.
        In this test, TN play a Roll of the Router.
        
        Physical Network configuration
        
        ---------------------------------------
                |               |
                NUT             TN

        Logical Network Configuration

                                HOST A (globaladdress:A)
                                |
        ----------------------------------
                        |
                        Router
                        |
        ----------------------------------
                | 
                NUT (globaladdress:B)

        NUT < --- Router --- > HOST A

        In this configuration, Packets are send and received.

        for example,
                In Logical
                        HOST A           -- Echo Reply --> NUT
                Actually, in physical
                        TN (as Router X) -- Echo Reply --> NUT

INITIALIZATION

        There are 2 patterns for initialize.

        -- Test for host --

        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                      
   
          Wait (5 sec.)
                 Ignoring DAD packets for global address.

        -- Test for router --

        TN attempt to execute remote command 'vRemote(route.rmt)'.
        
        'route add -inet6 3ffe:501:ffff:109 TN'slink-local-address'

TEST PROCEDURE

        "checkPMTUincrease" verifies that the node attempts to detect
         increase of Path MTU.

        - NUT must not attempt to detect an increase less than 5 
          minutes after a Too Big Mesg.

        TN                      NUT

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

        1.
        TN send Echo Request.  
        
         === echo request ===>

        2.
        NUT send Echo Reply.

        <=== echo reply ===

        3.
        TN send ICMPv6 Too Big Mesg include MTU (1300).
        
         === ICMPv6 Too Big Mesg ===>

        4. 
        TN sleep 295 seconds in perl script.

        5.1
        TN send Echo Request which is fragmented.
        orignal packet's size is 1500 (ether's Link MTU.

         === echo request 1st ===>

         === echo request 2nd ===>

        5.2
        NUT send Echo Reply 
        << JUDGMENT >>
         <=== echo reply 1st ===

         <=== echo reply 2nd ===

        - NUT attemp to detect an increase of Path MTU at infrequent 
          intervals. The recommended se

        TN                      NUT

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

        1.
        TN send Echo Request.  
        
         === echo request ===>

        2.
        NUT send Echo Reply.

        <=== echo reply ===

        3.
        TN send ICMPv6 Too Big Mesg include MTU (1300).
        
         === ICMPv6 Too Big Mesg ===>

        4. 
        TN sleep 900 seconds in perl script.

                why 900 second ?
                The recommended setting for this timer is 10 minutes.

        5.1
        TN send Echo Request which is fragmented.
        orignal packet's size is 1500 (ether's Link MTU.

         === echo request 1st ===>

         === echo request 2nd ===>

        5.2
        NUT send Echo Reply 
        << JUDGMENT >>
         <=== echo reply ===

JUDGMENT

        << PASS >>
                NUT send Echo Reply which is no fragmented.
                node detects the increase of Path MTU.