MN-2-2-2-1-001 - BU of de-registration accepted (Status = 0)
Host
|
R CN0
| |
-----+-------+--------+---------------- LinkZ
|
R2 NUTY
| |
-----+-------+-----------------+------- LinkY
|
R1 NUTX
| |
-----+-------+-----------------+------- LinkX
|
HA0 Node0 NUT0
| | |
----------------------+---------------+---------+------- Link0
| Link0 |
3ffe:501:ffff:100::/64 |
home link |
| LinkX |
3ffe:501:ffff:102::/64 |
|
| LinkY |
3ffe:501:ffff:103::/64 |
|
| LinkZ |
3ffe:501:ffff:104::/64 |
|
| HA0(Link0) |
3ffe:501:ffff:100:200:ff:fe00:a0a0 |
|
| Node0(Link0) |
3ffe:501:ffff:100:200:ff:fe00:a3a3 |
|
| R1(LinkX) |
3ffe:501:ffff:102:200:ff:fe00:a4a4 |
|
| R2(LinkY) |
3ffe:501:ffff:103:200:ff:fe00:a6a6 |
|
| CN0(LinkZ) |
3ffe:501:ffff:104:200:ff:fe00:a8a8 |
|
1. Selection Option
- none
2. Position of Mobile Node
HA0 NUT0 R1 R2 CN0
| | | | |
| ----> | | | | 1.Router Advertisement
| | | | |
| NUTX | | |
| | | | |
| | <---- | | | 2.Router Advertisement
| | | | |
| <---- | | | | 3.Neighbor Solicitations
| | | | | 4.(no reply:3 seconds)
| | | | |
| <---- | | | | 5.Binding Update
| ----> | | | | 6.Binding Acknowledgement
| | | | |
1. Send Router Advertisement. (HA0 -> HA0_allnode_multi)
2. Send Router Advertisement. (R1 -> R1_allnode_multi)
3. Receive Neighbor Solicitations. (NUT0 -> HA0)
4. (no reply)
# Wait during a maximum of 3 seconds(RFC2461).
5. Receive Binding Update. (NUTX -> HA0)
6. Send Binding Acknowledgement. (HA0 -> NUTX)
HA0 NUTX R1 R2 CN
| | | | |
| | <---- | | | 1.Router Advertisement
| | | | |
| NUT0 | | |
| | | | |
| ----> | | | | 2.Router Advertisement
| | | | |
| | ----> | | | 3.Neighbor Solicitations
| | | | | 4.(no reply:3 seconds)
| | | | |
| <---- | | | | 5.Binding Update
| ----> | | | | 6.Binding Acknowledgement
| | | | |
| <---- | | | | 7.Neighbor Advertisement(*1)
| | | | |
1. Send Router Advertisement. (R1 -> R1_allnode_multi)
2. Send Router Advertisement. (HA0 -> HA0_allnode_multi)
3. Receive Neighbor Solicitations. (NUTX -> R1)
4. (no reply)
# Wait during a maximum of 3 seconds(RFC2461).
5. Receive Binding Update. (NUT0 -> HA0)
6. Send Binding Acknowledgement. (HA0 -> NUT0)
# The Destination Address is set to the home address.
# The Status field is set to 0(Binding Update accepted).
# The Sequence # field is set to the Sequence # in the Binding Update[5].
# The Lifetime field is set to 0.
# The Binding Authorization Data mobility option is not included.
# The Binding Refresh Advice mobility option is not included.
7. Receive Neighbor Advertisement. (NUT0 -> HA0_allnode_multi)
Packet Format is:
6. Binding Acknowledgement
7.Neighbor Advertisement is:
IPv6 header
Source Address = (home address)
Destination Address = (all node multicast address)
ICMPv6 header
Neighbor Advertisement
S = 0
O = 1
Target Address = (home address)
Link-layer address option
LinkLayerAddress = (link-layer address of NUT0)
(*1) PASS: HA0 receive Neighbor Advertisement.
(draft-ietf-mobileip-ipv6-24.txt)
11.7.3 Receiving Binding Acknowledgements
Upon receiving a packet carrying a Binding Acknowledgement, a mobile
node MUST validate the packet according to the following tests:
o The packet meets the authentication requirements for Binding
Acknowledgements, defined in Section 6.1.8 and Section 5. That
is, if the Binding Update was sent to the home agent, underlying
IPsec protection is used. If the Binding Update was sent to the
correspondent node, the Binding Authorization Data mobility option
MUST be present and have a valid value.
o The Binding Authorization Data mobility option, if present, MUST
be the last option and MUST not have trailing padding.
o The Sequence Number field matches the Sequence Number sent by the
mobile node to this destination address in an outstanding Binding
Update.
Any Binding Acknowledgement not satisfying all of these tests MUST be
silently ignored.
When a mobile node receives a packet carrying a valid Binding
Acknowledgement, the mobile node MUST examine the Status field as
follows:
o If the Status field indicates that the Binding Update was accepted
(the Status field is less than 128), then the mobile node MUST
update the corresponding entry in its Binding Update List to
indicate that the Binding Update has been acknowledged; the mobile
node MUST then stop retransmitting the Binding Update. In
addition, if the value specified in the Lifetime field in the
Binding Acknowledgement is less than the Lifetime value sent in
the Binding Update being acknowledged, then the mobile node MUST
subtract the difference between these two Lifetime values from the
remaining lifetime for the binding as maintained in the
corresponding Binding Update List entry (with a minimum value for
the Binding Update List entry lifetime of 0). That is, if the
Lifetime value sent in the Binding Update was L_update, the
Lifetime value received in the Binding Acknowledgement was L_ack,
and the current remaining lifetime of the Binding Update List
entry is L_remain, then the new value for the remaining lifetime
of the Binding Update List entry should be
max((L_remain - (L_update - L_ack)), 0)
where max(X, Y) is the maximum of X and Y. The effect of this
step is to correctly manage the mobile node's view of the
binding's remaining lifetime (as maintained in the corresponding
Binding Update List entry) so that it correctly counts down from
the Lifetime value given in the Binding Acknowledgement, but with
the timer countdown beginning at the time that the Binding Update
was sent.
Mobile nodes SHOULD send a new Binding Update well before the
expiration of this period in order to extend the lifetime. This
helps to avoid disruptions in communications, which might
otherwise be caused by network delays or clock drift.
o Additionally, if the Status field value is 1 (Accepted but prefix
discovery necessary), the mobile node SHOULD send a Mobile Prefix
Solicitation message to update its information about the available
prefixes.
o If the Status field indicates that the Binding Update was rejected
(the Status field is greater than or equal to 128), then the
mobile node can take steps to correct the cause of the error and
retransmit the Binding Update (with a new Sequence Number value),
subject to the rate limiting restriction specified in Section
11.8. If this is not done, or it fails, then the mobile node
SHOULD record in its Binding Update List that future Binding
Updates SHOULD NOT be sent to this destination.
11.5.4 Returning Home
(snip)
After receiving the Binding Acknowledgement for its Binding Update to
its home agent, the mobile node MUST multicast onto the home link (to
the all-nodes multicast address) a Neighbor Advertisement [12], to
advertise the mobile node's own link-layer address for its own home
address. The Target Address in this Neighbor Advertisement MUST be
set to the mobile node's home address, and the Advertisement MUST
include a Target Link-layer Address option specifying the mobile
node's link-layer address. The mobile node MUST multicast such a
Neighbor Advertisement for each of its home addresses, as defined by
the current on-link prefixes, including its link-local address and
site-local address. The Solicited Flag (S) in these Advertisements
MUST NOT be set, since they were not solicited by any Neighbor
Solicitation. The Override Flag (O) in these Advertisements MUST be
set, indicating that the Advertisements SHOULD override any existing
Neighbor Cache entries at any node receiving them.