NAME

ncStateByRs4Probe - Verifying State Machine: RS vs. PROBE


TARGET

  Router Only


SYNOPSIS

  ncStateByRs4Probe.seq [-tooloption ...] -p ncStateByRs4Probe.def


INITIALIZATION

  1. Set the state of neighbor cache entry to REACHABLE.
  2. 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)
<=== echo-reply ==== src=NUT's link-local dst=TN's link-local timeout: 2 sec
Wait (REACHABLE_TIME * MAX_RANDOM_FACTOR)
State: STALE (for TN)
==== echo-request ===> src=TN's link-local dst=NUT's link-local
<=== echo-reply ==== src=NUT's link-local dst=TN's link-local timeout: 2 sec
State: DELAY (for TN)
Wait (DELAY_FIRST_PROBE_TIME)
State: PROBE (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)
<=== echo-reply ==== src=NUT's link-local dst=TN's link-local timeout: 2 sec
Wait (REACHABLE_TIME * MAX_RANDOM_FACTOR)
State: STALE (for TN)
==== echo-request ===> src=TN's link-local dst=NUT's link-local
<=== echo-reply ==== src=NUT's link-local dst=TN's link-local timeout: 2 sec
State: DELAY (for TN)
Wait (DELAY_FIRST_PROBE_TIME)
State: PROBE (for TN)


TEST PROCEDURE

ncStateByRs4Probe verifies that state transition for a NUT in PROBE state when receiving an RS.

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

State: PROBE (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      PROBE      unchanged Not mentioned
                                                       in RFC2461
  ---------+-----------+---------+----------+---------+-----------------
  TN's link all-router  same      PROBE      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.


SEE ALSO

  perldoc V6evalTool
  perldoc V6evalRemote