NAME

hostRecvRedirectInvalid - Verifying invalid redirects vs neighbor cache entry

TARGET

Host only

INITIALIZATION

Clear a neighbor cache entry for TN.
Set R1 as the default router, and its state to REACHABLE.

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


  State: No neighbor cache entry (for R1, TN)


  ==== unsolicited RA ===>
       src=R1's link-local
       dst=all-node
       M=0, O=0
       RouterLifetime=600
       ReachableTime=0
       RetransTimer=0
       w/ SLLA
       Prefix Option:
           L=1, A=1
           ValidLifetime=2592000
           PreferredLifetime=604800
           Prefix=3ffe:501:ffff:100::/64


  State: STALE (for R1), No neighbor cache entry (for TN)


  ==== solicited NA ===>
        src=R1's link-local
        dst=NUT's link-local
        R=1, S=1, O=1
        target=R1's link-local
        TLLA=R1's LLA


  State: REACHABLE (for R1), No neighbor cache entry (for TN)


  Wait (3 sec) for DAD NS

TEST PROCEDURE

hostRecvRedirectInvalid verifies that no neighbor cache entry is created with invalid redirect messages.

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


  State: REACHABLE (for R1), No neighbor cache entry (for TN)


  ==== invalid redirect ===>
       ICMP Target=TN's link-local


  Judgment: Examining NUT has no neighbor cache entry

JUDGMENT


 1. Invalid redirect messages
 ================+================+=========+====+========+==========+===============+===========
 IP                                         |ICMP                                    |NC state
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 Src             |Dst             |Hop Limit|Code|Chksum  |Dst       |Target         |Now  |New
 ================+================+=========+====+========+==========+===============+===========
 *R1's global    |NUT's link-local|255      |0   |valid   |off-link  |TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+----
 R1's link-local |NUT's link-local|*!=255   |0   |valid   |off-link  |TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 R1's link-local |NUT's link-local|255      |*!=0|valid   |off-link  |TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 R1's link-local |NUT's link-local|255      |0   |*invalid|off-link  |TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 R1's link-local |NUT's link-local|255      |0   |valid   |*multicast|TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 *R2's link-local|NUT's link-local|255      |0   |valid   |off-link  |TN's link-local|none |none 
 ----------------+----------------+---------+----+--------+----------+---------------+-----+-----
 R1's link-local |NUT's link-local|255      |0   |valid   |*off-link |*TN's global   |none |none 
 ================+================+=========+====+========+==========+===============+===========

TERMINATION

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

NOTE

  The test does not invoke any remote command.

REFERENCE

RFC2461

8.1.  Validation of Redirect Messages

   A host MUST silently discard any received Redirect message that does
   not satisfy all of the following validity checks:

      - IP Source Address is a link-local address.  Routers must use
        their link-local address as the source for Router Advertisement
        and Redirect messages so that hosts can uniquely identify
        routers.

      - The IP Hop Limit field has a value of 255, i.e., the packet
        could not possibly have been forwarded by a router.

      - If the message includes an IP Authentication Header, the message
        authenticates correctly.

      - ICMP Checksum is valid.

      - ICMP Code is 0.

      - ICMP length (derived from the IP length) is 40 or more octets.

      - The IP source address of the Redirect is the same as the current
        first-hop router for the specified ICMP Destination Address.

      - The ICMP Destination Address field in the redirect message does
        not contain a multicast address.

      - The ICMP Target Address is either a link-local address (when
        redirected to a router) or the same as the ICMP Destination
        Address (when redirected to the on-link destination).

      - All included options have a length that is greater than zero.