verifies that that NUT send a redirect message
if NUT know the better router's link-local address.
=begin html
TN NUT
--------------------
==== echo-request to H3 ===>
TN throws an echo-request to NUT
mac src=TN
mac dst=NUT
ip src=TN's global
ip dst=H3's global
<=== NS for R1 (if any) ====
src=NUT's link-local
dst=R1's link-local
target=R1's link-local
w/ SLLA
==== NA for R1 (if any) ===>
src=R1's link-local
dst=NUT's link-local
target=R1's link-local
R=1, S=1, O=1
w/ TLLA
<=== echo-request to H3 ====
NUT forwards an echo-request to R1
mac src=NUT
mac dst=R1
ip src=TN's global
ip dst=H3's global
<=== NS for TN (if any) ====
src=NUT's link-local
dst=solicited-node[TN's global]
target=TN's global
w/ SLLA
==== NA for TN (if any) ===>
src=TN's global
dst=NUT's link-local
target=TN's global
R=0, S=1, O=1
w/ TLLA
<=== Redirect ====
src=NUT's link-local
dst=TN's global
target=R1's link-local
icmp dst=H3's global
w/ OR w/o TLLA
w/ OR w/o Redirected header
=end html
=head1 JUDGMENT
=begin html
1. NUT must forwards an echo-request to the better router, R1:
2. NUT must send a redirect message to TN:
ip src=NUT's link-local
ip dst=TN's global
icmp target=R1's link-local
icmp dst=H3's global
=end html
=head1 TERMINATION
N/A
=head1 NOTE
NUT may send a redirect message that contains a redirected header option,
but whose hop limit value is decreased from the original one.
It does make sense. In such case, this test will judges "WARN" instead of
"PASS" to notify the difference.
=head1 REFERENCE
=begin html
RFC2461
8.2. Router Specification
A router SHOULD send a redirect message, subject to rate limiting,
whenever it forwards a packet that is not explicitly addressed to
itself (i.e. a packet that is not source routed through the router)
in which:
- the Source Address field of the packet identifies a neighbor,
and
- the router determines that a better first-hop node resides on
the same link as the sending node for the Destination Address of
the packet being forwarded, and
- the Destination Address of the packet is not a multicast
address, and
The transmitted redirect packet contains, consistent with the message
format given in Section 4.5:
- In the Target Address field: the address to which subsequent
packets for the destination SHOULD be sent. If the target is a
router, that router's link-local address MUST be used. If the
target is a host the target address field MUST be set to the
same value as the Destination Address field.
- In the Destination Address field: the destination address of the
invoking IP packet.
- In the options:
o Target Link-Layer Address option: link-layer address of the
target, if known.
o Redirected Header: as much of the forwarded packet as can
fit without the redirect packet exceeding 1280 octets in
size.
A router MUST limit the rate at which Redirect messages are sent, in
order to limit the bandwidth and processing costs incurred by the
Redirect messages when the source does not correctly respond to the
Redirects, or the source chooses to ignore unauthenticated Redirect
messages. More details on the rate-limiting of ICMP error messages
can be found in [ICMPv6].
=end html
=head1 SEE ALSO
perldoc V6evalTool
perldoc V6evalRemote
=cut