NAME

  Test v6LC.2.1.1 - On-link Determination
  Part C: Global Address, On-link Prefix does not cover TN2

Purpose

   Verify that a node correctly determines that a destination is on-link.

References

  * [IPv6-ARCH]  Section 2.4
  * [ND]  Section 5.2

Resource Requirements

  * Packet generator
  * Monitor to capture packets

Test Setup

  No Common Test Setup is performed. If the NUT is a router, configure a default route
  with TR1 as next hop. The Common Test Cleanup is performed after each part.

Packet A
IPv6 Header
Next Header: 58
Source Address: TN1's Link-local Address

ICMPv6 Echo Request

Packet B
IPv6 Header
Next Header: 58
Source Address: TN1's Global Address

ICMPv6 Echo Request

Router Advertisement
IPv6 Header
Next Header: 58

Router Advertisement
Prefix Length: 64
L Bit: 1 (on-link)
Prefix: TN1's Global Prefix

Packet C
IPv6 Header
Next Header: 58
Source Address: TN2's
Global Address
Destination Address: NUT's Global Address

ICMPv6 Echo Request

Router Advertisement
IPv6 Header Next Header: 58
Router Advertisement Prefix Length: 64 L Bit: 1 (on-link) Prefix: TN1's Global Prefix

Packet C
IPv6 Header Next Header: 58 Source Address: TN2's Global Address Destination Address: NUT's Global Address
ICMPv6 Echo Request

Procedure

  Part C: Global Address, On-link Prefix does not cover TN2
   6. If the NUT is a host, TR1 transmits the Router Advertisement. The Prefix Advertisement does not
      cover TN2's global address.
   7. TN2 transmits Packet C, an Echo Request with TN2's global source address.
   8. Observe the packets transmitted by the NUT.

Observable Results

  Part C
   Step 8:
   TN2's global address is not covered by the on-link prefix. Hence, the NUT should
   consider TN2's global address as off-link. The NUT should send a Neighbor Solicitation
   with Target Address equal to TR1's link-local address indicating that the NUT has
   successfully determined that TN2 was off-link.

Possible Problems

   Part C, there are core routers that when a default route is configured Neighbor Solicitations 
   are sent to populate the Neighbor Cache, when no response is given they may follow 7048. Which 
   allows a backing off mechanism for transmitting Neighbor Solicitations when there is no answer. 
   The test case may be run answering the initial NS when the route is installed and then observe 
   the packet being transmitted to the first hop