NAME

  mcastOne - Verify that a node properly chooses the PMTU for multicast 
             destinations when receiveng PTB messages from more than one router.

TARGET

  Host and Router

SYNOPSIS

  mcastOne.seq [-tooloption ...] -pkt mcastOne.def
    -tooloption : v6eval tool option

INITIALIZATION

        If the NUT is a host, send a Router Advertisment.
        If the NUT is a router, configure a default route with TN as the next hop.
        And make state of Neighbor Cashe Entry for TN's addresses reachable.

TEST PROCEDURE

   TR1                         NUT
    |                           |
    |<--------------------------|
    |   1.Echo Request          |
    |   (1500 octets)           |
    |                           |
    |-------------------------->|
    |   2.Packet Too Big        |
    |   (MTU is 1450)           |
    |                           |
    |<--------------------------|
    | 3.Fragmented Echo Request |
    |   (1st + 2nd = 1500)      |
    |                           |
    |-------------------------->|
    |   4.Packet Too Big        |
    |   (MTU is 1400)           |
    |                           |
    |<--------------------------|
    | 5.Fragmented Echo Request |
    |   (1st + 2nd = 1500)      |
    |                           |
    |<--------------------------|
    |    6.Echo Request         |
    |    (1400 octets)          |
    |                           |
    |-------------------------->|
    |   7.Packet Too Big        |
    |   (MTU is 1300)           |
    |                           |
    |<--------------------------|
    | 8.Fragmented Echo Reply   |
    |   (1st + 2nd = 1400)      |
    |                           |
    |-------------------------->|
    |   9.Packet Too Big        |
    |   (MTU is 1350)           |
    |                           |
    |<--------------------------|
    | 10.Fragmented Echo Reply  |
    |   (1st + 2nd = 1400)      |
    |                           |
    v                           v

  1. Receive Echo Request <<Check 1>>
  2. Send Packet Too Big message
  3. Receive fragmented Echo Request <<Check 2>>
  4. Send Packet Too Big message
  5. Receive fragmented Echo Request <<Check 3>>
  6. Receive Echo Request <<Check 4>>
  7. Send Packet Too Big message
  8. Receive fragmented Echo Request <<Check 5>>
  9. Send Packet Too Big message
 10. Receive fragmented Echo Request <<Check 6>>

  Packet Too Big message is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 1280
            NextHeader         = 58 (ICMPv6)
            SourceAddress      = TR1's Global Address
            DestinationAddress = NUT's Global Address

        ICMP Echo Request
            Type           = 2 (Packet Too Big)
            Code           = 0xff
            Checksum       = (auto)
            MTU            = 1280
            PayloadData    = (1232 octets)

JUDGEMENT

  PASS: <<Check 1>> Echo Request Received or Fragmented Echo Request Received
        <<Check 2>> Fragmented Echo Request Received.1st and 2nd fragment no larger than 1450 octets.
        <<Check 3>> Fragmented Echo Request Received.1st and 2nd fragment no larger than 1400 octets.
        <<Check 4>> Echo Request Received or Fragmented Echo Request Received
        <<Check 5,6>> Fragmented Echo Request Received.1st and 2nd fragment no larger than 1300 octets.

  Echo Request Data is:

        IPv6 Header
            Version            = 6
            Traffic Class      = 0
            FlowLabel          = 0
            PayloadLength      = 1460,1360
            NextHeader         = 58 (ICMPv6)
            SourceAddress      = NUT's Global Address
            DestinationAddress = Multicast Address(FF1E::1:2)

        ICMP Echo Request
            Type           = 128 (Echo Request)
            Code           = 0
            Checksum       = (auto)
            Identifier     = 0xffff
            SequenceNumber = 1
            PayloadData    = (1452,1352 octets)

REFERENCE

RFC 1981 - Path MTU Discovery for IPv6