NAME

ncStateByRs4Reachable - Verifying State Machine: RS vs. REACHABLE

TARGET

  Router Only

SYNOPSIS

  ncStateByRs4Reachable.seq [-tooloption ...] -p ncStateByRs4Reachable.def

INITIALIZATION

Set the state of neighbor cache entry to REACHABLE.
Cache either TN's LLA, or a bogus LLA

Cache a LLA of TN

  TN                 NUT
  ----------------------


  State: NONCE (for TN)


  ==== echo-request ===>
        src=TN's link-local
        dst=NUT's link-local


  State: INCOMPLETE (for TN)


  <=== multicast NS ====
        src=NUT's link-local
        dst=solicited-node[TN's link-local]
        target=TN's link-local
        w/ SLLA
        timeout: RETRANS_TIMER * MAX_MULTICAST_SOLICIT


  ==== solicited NA ===>
        src=TN's link-local
        dst=NUT's link-local
        target=TN's link-local
        TLLA=TN's LLA


  State: REACHABLE (for TN)

Cache a bogus LLA

  TN                 NUT
  ----------------------


  State: NONCE (for TN)


  ==== echo-request ===>
        src=TN's link-local
        dst=NUT's link-local


  State: INCOMPLETE (for TN)


  <=== multicast NS ====
        src=NUT's link-local
        dst=solicited-node[TN's link-local]
        target=TN's link-local
        w/ SLLA
        timeout: RETRANS_TIMER * MAX_MULTICAST_SOLICIT


  ==== solicited NA ===>
        src=TN's link-local
        dst=NUT's link-local
        target=TN's link-local
        TLLA=a bogus LLA


  State: REACHABLE (for TN)

TEST PROCEDURE

ncStateByNa4Reachable verifies that state transition for a NUT in REACHABLE state when receiving an RS.

  TN                 NUT
  ----------------------


  State: REACHABLE (for TN)


  ==== RS ===>


  Judgment: Examining NUT's neighbor cache state

JUDGMENT


  ===============================+==========+=========+=================
  RS                             |New State |LLA       Comments
  ---------+-----------+---------+          |
  Source IP|Destination|SLLA     |          |
           |IP         |         |          |
  =========+===========+=========+==========+=========*=================
  TN's link all-router  none      REACHABLE  unchanged Not mentioned
                                                       in RFC2461
  ---------+-----------+---------+----------+---------+-----------------
  TN's link all-router  same      REACHABLE  unchanged
  ---------+-----------+---------+----------+---------+-----------------
  TN's link all-router  different STALE      updated
  =========+===========+=========+==========+=========+=================

TERMINATION

N/A

NOTE

TBD

REFERENCE

6.2.6.  Processing Router Solicitations


   Router Solicitations in which the Source Address is the unspecified
   address MUST NOT update the router's Neighbor Cache; solicitations
   with a proper source address update the Neighbor Cache as follows. If
   the router already has a Neighbor Cache entry for the solicitation's
   sender, the solicitation contains a Source Link-Layer Address option,
   and the received link-layer address differs from that already in the
   cache, the link-layer address SHOULD be updated in the appropriate
   Neighbor Cache entry, and its reachability state MUST also be set to
   STALE.  If there is no existing Neighbor Cache entry for the
   solicitation's sender, the router creates one, installs the link-
   layer address and sets its reachability state to STALE as specified
   in Section 7.3.3.  Whether or not a Source Link-Layer Address option
   is provided, if a Neighbor Cache entry for the solicitation's sender
   exists (or is created) the entry's IsRouter flag MUST be set to
   FALSE.