NAME

HA_7_2_1 - Receiving Local RA Msgs w/ HA Info opt (preference=0)

TARGET

Router

TOPOLOGY

       NUT
        |
--------+-------+-------+-------+-------+------- Link0
                |       |       |       |
                R0     MN0     HA0     CN0
                |
        --------+-------+----------------------- Link0X
                        |
                       MN0X
Link0 global 3ffe:501:ffff:100::/64 home link
Link0X global 3ffe:501:ffff:1100::/64 foreign link
R0 (Link0) global 3ffe:501:ffff:100::a0a0  
ether 00:00:00:00:a0:a0
MN0 global 3ffe:501:ffff:100:200:ff:fe00:a2a2 home address
CN0 global 3ffe:501:ffff:100:<TnDef.Link0_addr>  
link-local fe80::<TnDef.Link0_addr>
ether <TnDef.Link0_addr>
HA0 global 3ffe:501:ffff:100:200:ff:fe00:a3a3  
link-local fe80::200:ff:fe00:a3a3
ether 00:00:00:00:a3:a3
MN0X global 3ffe:501:ffff:1100:200:ff:fe00:a2a2 care-of address

INITIALIZATION

Check Link0 routing table 
  NUT
(Link0)   HA0     CN0     MN0X
   |       |       |       |
   | <-------------------- | Echo Request
   | --------------------> | Echo Reply
   |       |       |       |
   | <------------ |       | RS
   | ------------> |       | RA (preference=10)
   | <---- |       |       | RA (preference=0)
   |       |       |       |


1. MN0X sends Echo Request
2. MN0X receives Echo Reply
3. CN0 sends RS
4. CN0 receives RA
5. HA0 sends RA

TEST PROCEDURE

Check DHAAD 
  NUT
(Link0)   MN0X
   |       |
   | <---- | HAAD Request
   | ----> | HAAD Reply
   |       |


1. MN0X sends HAAD Request
    packet format is:
        ICMP_HAAD_request_message_format_from_MN_to_HA.gif
2. MN0X receives HAAD Reply
    packet format is:
        ICMP_HAAD_reply_message_format_form_HA_to_MN.gif

JUDGEMENT

PASS: MN0X receives HAAD Reply

REFERENCE

10.5.1 Receiving Router Advertisement Messages 
   For each link on which a router provides service as a home agent, the
   router maintains a Home Agents List recording information about all
   other home agents on that link.  This list is used in the dynamic
   home agent address discovery mechanism, described in Section 10.5.
   The information for the list is learned through receipt of the
   periodic unsolicited multicast Router Advertisements, in a manner
   similar to the Default Router List conceptual data structure
   maintained by each host for Neighbor Discovery [12].  In the
   construction of the Home Agents List, the Router Advertisements are
   from each other home agent on the link, and the Home Agent (H) bit is
   set in them.

   On receipt of a valid Router Advertisement, as defined in the
   processing algorithm specified for Neighbor Discovery [12], the home
   agent performs the following steps, in addition to any steps already
   required of it by Neighbor Discovery:

   o  If the Home Agent (H) bit in the Router Advertisement is not set,
      delete the sending node's entry in the current Home Agents List
      (if one exists).  Skip all the following steps.

   o  Otherwise, extract the Source Address from the IP header of the
      Router Advertisement.  This is the link-local IP address on this
      link of the home agent sending this Advertisement [12].

   o  Determine the preference for this home agent.  If the Router
      Advertisement contains a Home Agent Information Option, then the
      preference is taken from the Home Agent Preference field in the
      option; otherwise, the default preference of 0 MUST be used.

   o  Determine the lifetime for this home agent.  If the Router
      Advertisement contains a Home Agent Information Option, then the
      lifetime is taken from the Home Agent Lifetime field in the
      option; otherwise, the lifetime specified by the Router Lifetime
      field in the Router Advertisement SHOULD be used.

   o  If the link-local address of the home agent sending this
      Advertisement is already present in this home agent's Home Agents
      List and the received home agent lifetime value is zero,
      immediately delete this entry in the Home Agents List.

   o  Otherwise, if the link-local address of the home agent sending
      this Advertisement is already present in the receiving home
      agent's Home Agents List, reset its lifetime and preference to the
      values determined above.

   o  If the link-local address of the home agent sending this
      Advertisement is not already present in the Home Agents List
      maintained by the receiving home agent, and the lifetime for the
      sending home agent is non-zero, create a new entry in the list,
      and initialize its lifetime and preference to the values
      determined above.

   o  If the Home Agents List entry for the link-local address of the
      home agent sending this Advertisement was not deleted as described
      above, determine any global address(es) of the home agent based on
      each Prefix Information option received in this Advertisement in
      which the Router Address (R) bit is set (Section 7.2).  Add all
      such global addresses to the list of global addresses in this Home
      Agents List entry.

   A home agent SHOULD maintain an entry in its Home Agents List for
   each valid home agent address until that entry's lifetime expires,
   after which time the entry MUST be deleted.