Aerohive Networks Aerohive AP141, Hardware Reference Manual

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Hardware Reference Guide 67
AP340 P
RODUCT
O
VERVIEW
Smart PoE
The AP320, AP340, and BR200-WP apply the Aerohive concept of smart PoE to adjust power consumption as
necessitated by varying levels of available power. The AP340 and BR200-WP support PoE on the ETH0 or ETH1
interfaces and can draw power through either one or through both simultaneously. Based on the available
power that the device detects, it manages its internal power use by making the following adjustments:
•
No adjustments are needed when the power level is 20 W (watts) or higher. If the available power drops
to a range between 18 and 20 W, the device disables its ETH1 interface, assuming that it is drawing
power through its ETH0 interface. If it is drawing power solely through its ETH1 interface, then it disables its
ETH0 interface instead.
• If the power level drops to the 15 – 18 W range, the device then switches from 3x3 MIMO (Multiple In,
Multiple Out) to 2x3 (see "Configuring Antennas" on page 71 ).
• In rare cases when the power drops between 13.6 and 15 W and further power conservation is
necessary, the device reduces the speed on its active Ethernet interface—ETH0 or ETH1—from
10/100/1000 Mbps to 10/100 Mbps.
• Finally, in the event that there is a problem with the PoE switch or Ethernet cable and the power falls
between 0 and 13.6 W, the device disables its wireless interfaces and returns its ETH0 and ETH1 interfaces
to 10/100/1000 Mbps speeds.
Through the application of smart PoE, the device can make power usage adjustments so that it can
continue functioning even when the available power level drops.
Aggregate and Redundant Interfaces
By default ETH0 and ETH1 act as two individual Ethernet interfaces. When both interfaces are connected to
the network and are in backhaul mode, the AP transmits broadcast traffic only through ETH0. The AP
transmits broadcast traffic through ETH1 only when ETH0 does not have network connectivity. When both
Ethernet interfaces are connected to the network and are in access mode, then the AP transmits broadcast
traffic through all the access interfaces: ETH0, ETH1, and all wireless subinterfaces in access mode.
In addition to using ETH0 and ETH1 as individual interfaces, you can combine them into an aggregate
interface (agg0) to increase throughput, or combine them into a redundant interface (red0) to increase
reliability. The logical red0 and agg0 interfaces support all the settings that you can configure for Ethernet
interfaces except those pertaining to physical link characteristics such as link speed. See the sections below
for configuration information.
Aggregate Interface
You can increase throughput onto the wired network by combining ETH0 and ETH1 into a single logically
aggregated interface called "agg0". The aggregate interface effectively doubles the bandwidth that each
physical interface has when used individually. In this configuration, both Ethernet ports actively forward
traffic, the AP applying an internal scheduling mechanism based on the source MAC address of each
packet to send traffic through the aggregate member interfaces. To configure an aggregate interface,
enter the following commands:
interface eth0 bind agg0
interface eth1 bind agg0
In addition to configuring the AP, you must also configure the connecting switch to support EtherChannel.
For example, the following commands bind two physical Ethernet ports—0/1 and 0/2—to the logical
interface port-channel group 1 on a Cisco Catalyst 2900 switch running Cisco IOS 12.2:
Switch#conf t
Switch(config)#interface port-channel 1
Switch(config-if)#switchport mode access
Switch(config-if)#spanning-tree portfast
Switch(config-if)#exit