NAME

recvNsRFlag - Verifing that a IsRouter flag is not modified by a NS

TARGET

Host only

SYNOPSIS

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

INITIALIZATION

1. Set the state of neighbor cache entry to REACHABLE whose IsRouter flag is true.
2. Cache either TN's LLA or a bogus LLA

Cache a LLA of TN

  TN                 NUT
  ----------------------
  State: NONCE (for TN)


  ==== unsolicited RA ===>
       src=TN's link-local
       dst=all-node
       M=0, O=0
       RouterLifetime=600
       ReachableTime=0
       RetransTimer=0
       SLLA=TN's LLA
       Prefix Option:
           L=1, A=1
	   ValidLifetime=2592000
	   PreferredLifetime=604800
           Prefix=3ffe:501:ffff:100::/64


  State: STALE (for TN)


  <=== Ns for DAD (if any) ====
       src=unspecified
       dst=solicited-node[NUT's global]
       target=NUT's global


  ==== NA ===>
       src=TN's link-local
       dst=NUT's link-local
       R=1, S=1, O=1
       target=TN's link-local
       TLLA=TN's LLA


  State: REACHABLE (for TN)

Cache a bogus LLA

  TN                 NUT
  ----------------------
  State: NONCE (for TN)


  ==== unsolicited RA ===>
       src=TN's link-local
       dst=all-node
       M=0, O=0
       RouterLifetime=600
       ReachableTime=0
       RetransTimer=0
       SLLA=a bogus LLA
       Prefix Option:
           L=1, A=1
	   ValidLifetime=2592000
	   PreferredLifetime=604800
           Prefix=3ffe:501:ffff:100::/64


  State: STALE (for TN)


  <=== Ns for DAD (if any) ====
       src=unspecified
       dst=solicited-node[NUT's global]
       target=NUT's global


  ==== NA ===>
       src=TN's link-local
       dst=NUT's link-local
       R=1, S=1, O=1
       target=TN's link-local
       TLLA=a bogus LLA


  State: REACHABLE (for TN)

TEST PROCEDURE

recvNsRFlag verifies that a IsRouter flag is NOT modified by a NS.

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


  State: REACHABLE (for TN)


  ==== NS ===>
       src=TN's link-local
       dst=teh NUT's link-local or solicited-node[NUT's link-local]
       target=NUT's link-local
       w/ or w/o SLL


  State: REACHABLE or STALE (for TN)


  ==== echo-request ===>
       src=off-link global, but LLA is TN's one
       dst=NUT's global


  <=== Judgement #2: echo-reply ====
       src=NUT's global
       dst=off-link global, but LLA is TN's one


  State: REACHABLE or DELAY->PROBE (for TN)


  <=== Ns for TN (if the state is PROBE) ====
       src=NUT's link-local
       dst=TN's link-local
       target=TN's global


  State: REACHABLE or NONCE (for TN)
=end html



JUDGEMENT

1. IsRouter flag MUST NOT be modified

7.2.3.  Receipt of Neighbor Solicitations


   If a Neighbor Cache entry is created the IsRouter flag SHOULD be set
   to FALSE.  This will be the case even if the Neighbor Solicitation is
   sent by a router since the Neighbor Solicitation messages do not
   contain an indication of whether or not the sender is a router.  In
   the event that the sender is a router, subsequent Neighbor
   Advertisement or Router Advertisement messages will set the correct
   IsRouter value.  If a Neighbor Cache entry already exists its
   IsRouter flag MUST NOT be modified.

  ========================+=====================
  Received NS             | a IsRouter flag
  by NUT                  | of NUT's NCE
  ------------+-----------+ ---------+----------
  Dst         | SLLA      | Current  | New
  ============+===========+==========+==========
  unicast     | none      | 1        | unchanged
  ------------+-----------+----------+----------
  unicast     | same      | 1        | unchanged
  ------------+-----------+----------+----------
  multicast   | none      | 1        | unchanged
  ------------+-----------+----------+----------
  multicast   | same      | 1        | unchanged
  ------------+-----------+----------+----------
  unicast     | different | 1        | unchanged
  ------------+-----------+----------+----------
  multicast   | different | 1        | unchanged
  ============+===========+==========+==========





  2. NUT sends an echo-reply that is thrown to
     the default router (i.e. TN).



TERMINATION

  Send RA with RouterLifetime=0 to clear the Default Router List.



NOTE

  The command does not invoke any remote command.



SEE ALSO

  perldoc V6evalTool
  perldoc V6evalRemote