Benefits Of Ieee 802.3Ad Link Bundling - Cisco ASR 920 Series Configuration Manual Ethernet Router

LACP Enhancements
On ports configured to use LACP, it tries to configure the maximum number of compatible ports in an
EtherChannel, up to the maximum allowed by the hardware. To use the hot standby feature in the event a
channel port fails, both ends of the LACP bundle must support the lacp max-bundle command.
As a control protocol, LACP uses the Slow Protocol Multicast address of 01-80-C2-00-00-02 to transmit
LACP protocol data units (PDUs). Aside from LACP, the Slow Protocol linktype is to be utilized by operations,
administration, and maintenance (OAM) packets, too. Subsequently, a subtype field is defined per the IEEE
802.3ad standard [1] (Annex 43B, section 4) differentiating LACP PDUs from OAM PDUs.
LACP and Port Aggregation Control Protocol (PAgP) are not compatible. Ports configured for PAgP
Note
cannot form port channels on ports configured for LACP, and ports configured for LACP cannot form
port channels on ports configured for PAgP.

Benefits of IEEE 802.3ad Link Bundling

• Increased network capacity without changing physical connections or upgrading hardware
• Cost savings from the use of existing hardware and software for additional functions
• A standard solution that enables interoperability of network devices
• Port redundancy without user intervention when an operational port fails
LACP Enhancements
The following LACP enhancements are supported:
• Four member links per LACP bundle.
• Cisco nonstop forwarding (NSF), and nonstop routing (NSR) on Gigabit EtherChannel bundles.
• Link failover time of 250 milliseconds or less and a maximum link failover time of 2 seconds; port
• Shutting down a port channel when the number of active links falls below the minimum threshold. In
• The IEEE Link Aggregation Group (LAG) MIB.
LACP for Gigabit Interfaces
The LACP (802.3ad) for Gigabit Interfaces feature bundles individual Ethernet links (Gigabit Ethernet or Ten
Gigabit Ethernet) into a single logical link that provides the aggregate bandwidth of up to four physical links.
All LAN ports on a port channel must be the same speed and must all be configured as either Layer 2 or Layer
3 LAN ports. If a segment within a port channel fails, traffic previously carried over the failed link switches
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channels remain in the LINK_UP state to eliminate reconvergence by the Spanning-Tree Protocol.
the port channel interface, a configurable option is provided to bring down the port channel interface
when the number of active links falls below the minimum threshold. For the port-channel state to be
symmetric on both sides of the channel, the peer must also be running LACP and have the same lacp
min-bundle command setting.
Configuring IEEE 802.3ad Link Bundling