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NAME : HCPLCPDU
DESCRIPTION: LinkAG LACP Protocol-Data-Unit (PDU) c/b
DSECT : LCPDU
FUNCTION : This control block maps the IEEE 802.3ad-2000
version 1 LACP PDU structure.
The Link Aggregation Control Protocol (LACP)
provides a standardized means for exchanging
information between Partner Systems on a link
to allow their Link Aggregation Control
instances to reach agreement on the identity
of the Link Aggregation Group to which the
link belongs, move the link to that Link
Aggregation Group, and enable its transmission
and reception functions in an orderly manner.
Destination Address (DA):
The DA in all LACP PDUs is the
Slow_Protocols_Multicast address (01-80-C2-00-00-02).
Source Address (SA):
The SA in LACP PDU is the individual MAC address
associated with the port from which the PDU is
transmitted.
Length/Type:
LACP PDUs are always type encoded, and carry the Slow
Protocol type field. The encoding of this type field
is 0x8809.
Subtype:
The Subtype field identifies the specific Slow
Protocol being encapsulated. LACP PDUs carry the
carry the subtype value 0x01.
Version number:
This identifies the LACP protocol version;
implementations conformant to IEEE 802.3ad of the
standard carry the value 0x01.
TLV_type = Actor Information:
This field indicates the nature of the information
carried in this TLVtuple. Actor information is
identified by the value 0x01.
Actor_Information_Length:
This field indicates the length (in bytes) of this
TLV-tuple, Actor information uses a length value of 20
(0x14).
Actor_System_Priority:
The priority assigned to this System (by management or
administration policy), encoded as an unsigned
integer.
Actor_System:
The Actor's System ID, encoded as a MAC address.
Actor_Key:
The operational Key value assigned to the port by the
Actor, encoded as an unsigned integer.
Actor_Port_Priority:
The priority assigned to this port by the Actor (the
System sending the PDU; assigned by management or
administration policy), encoded as an unsigned
integer.
Actor_Port:
The port number assigned to the port by the Actor (the
System sending the PDU), encoded as an unsigned
integer.
Actor_State:
The Actor's state variables for the port, encoded as
individual bits within a single byte, as follows:
1) LACP_Activity is encoded in bit 0. This flag
indicates the Activity control value with regard to
this link. Active LACP is encoded as a 1; Passive
LACP is encoded as a 0
2) LACP_Timeout is encoded in bit 1. This flag
indicates the Timeout control value with regard to
this link. Short Timeout is encoded as a 1; Long
Timeout is encoded as a
3) Aggregation is encoded in bit 2. If TRUE
(encoded as a 1), this flag indicates that the
System considers this link to be Aggregatable;
i.e., a potential candidate for aggregation. If
FALSE (encoded as a 0), the link is considered to
be Individual; i.e., this link can be operated only
as an individual link.
4) Synchronization is encoded in bit 3. If TRUE
(encoded as a 1), the System considers this link to
be IN_SYNC; i.e., it has been allocated to the
correct Link Aggregation Group, the group has been
associated with a compatible Aggregator, and the
identity of the Link Aggregation Group is
consistent with the System ID and operational Key
information transmitted. If FALSE (encoded as a
0), then this link is currently OUT_OF_SYNC; i.e.,
it is not in the right Aggregation.
5) Collecting is encoded in bit 4. TRUE (encoded as
a 1) means collection of incoming frames on this
link is definitely enabled; i.e., collection is
currently enabled and is not expected to be
disabled in the absence of administrative changes
or changes in received protocol information. Its
value is otherwise FALSE (encoded as a 0);
6) Distributing is encoded in bit 5. FALSE (encoded
as a 0) means distribution of outgoing frames on
this link is definitely disabled; i.e.,
distribution is currently disabled and is not
expected to be enabled in the absence of
administrative changes or changes in received
protocol information. Its value is otherwise TRUE
(encoded as a 1);
7) Defaulted is encoded in bit 6. If TRUE (encoded
as a 1), this flag indicates that the Actor's
Receive machine is using Defaulted operational
Partner information, administratively configured
for the Partner. If FALSE (encoded as a 0), the
operational Partner information in use has been
received in a LACPDU;
8) Expired is encoded in bit 7. If TRUE (encoded as
a 1), this flag indicates that the Actor's Receive
machine is in the EXPIRED state; if FALSE (encoded
as a 0), this flag indicates that the Actor's
Receive machine is not in the EXPIRED state.
NOTE-The received values of Defaulted and Expired
state are not used by LACP; however, knowing their
values can be useful when diagnosing protocol
problems.
Reserved:
These 3 bytes are reserved for use in future
extensions to the protocol. They shall be ignored on
receipt and shall be transmitted as zeroes to claim
compliance with Version 1 of this protocol.
TLV_type = Partner Information:
This field indicates the nature of the information
carried in this TLV-tuple. Partner information is
identified by the integer value 0x02.
Partner_Information_Length:
This field indicates the length (in bytes) of this
TLV-tuple, Partner information uses a length value of
20 (0x14).
Partner_System_Priority:
The priority assigned to the Partner System (by
management or administration policy), encoded as an
unsigned integer.
Partner_System:
The Partner's System ID, encoded as a MAC address.
Partner_Key:
The operational Key value assigned to the port
associated with this link by the Partner, encoded as
an unsigned integer.
Partner_Port_Priority:
The priority assigned to this port by the Partner (by
management or administration policy), encoded as an
unsigned integer.
Partner_Port:
The port number associated with this link assigned to
the port by the Partner, encoded as an unsigned
integer.
Partner_State:
The Actor's view of the Partner's state variables,
depicted in Figure 43-8 and encoded as individual bits
within a single byte, as defined for Actor_State.
Reserved:
These 3 bytes are reserved for use in future
extensions to the protocol. They shall be ignored on
receipt and shall be transmitted as zeroes to claim
compliance with Version 1 of this protocol.
TLV_type = Collector Information:
This field indicates the nature of the information
carried in this TLV-tuple. Collector information is
identified by the integer value 0x03
Collector_Information_Length:
This field indicates the length (in bytes) of this
TLV-tuple. Collector information uses a length value
of 16 (0x10).
CollectorMaxDelay:
This field contains the value of Collector Maximum
Delay of the station transmitting the LACPDU, encoded
as an unsigned integer number of tens of microseconds.
The range of values for this parameter is 0 to 65 535
tens of microseconds (0.65535 seconds).
Reserved:
These 12 bytes are reserved for use in future
extensions to the protocol. They shall be ignored on
receipt and shall be transmitted as zeroes to claim
compliance with Version 1 of this protocol.
TLV_type = Terminator:
This field indicates the nature of the information
carried in this TLV-tuple. Terminator (end of
message) information is identified by the integer
value 0x00.
Terminator_Length:
This field indicates the length (in bytes) of this
TLV-tuple. Terminator information uses a length value
of 0 (0x00).
Reserved.:
These 50 bytes are reserved for use in future
extensions to the protocol. They are ignored on
receipt and are transmitted as zeroes to claim
compliance with Version 1 of this protocol.
FCS:
This field is the Frame Check Sequence, typically
generated by the underlying MAC.
VM will create the packet without the FCS, as it
will be added/removed by OSA.
CREATED BY :
DELETED BY :
NCHORED -
RELOCATION CONSIDERATIONS : None
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