Cisco AJ732A - MDS 9134 Fabric Switch Configuration Manual page 206

Information About Port Channels
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Port-Channel Modes
Individual interfaces in port channels are configured with channel modes. When you run static port
channels, with no protocol, the channel mode is always set to on. After you enable LACP globally on
the device, you enable LACP for each channel by setting the channel mode for each interface to active
or passive. You can configure either channel mode for individual links in the LACP channel group.
Note You must enable LACP globally before you can configure an interface in either the active or passive
channel mode.
Table 11-2
Table 11-2
Channel Mode
passive
active
on
Both the passive and active modes allow LACP to negotiate between ports to determine if they can form
a port channel, based on criteria such as the port speed and the trunking state. The passive mode is useful
when you do not know whether the remote system, or partner, supports LACP.
Ports can form an LACP port channel when they are in different LACP modes as long as the modes are
compatible as in the following examples:
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Cisco Nexus 5000 Series Switch CLI Software Configuration Guide
11-6
higher port priority value means a lower priority for LACP. You can configure the port priority so
that specified ports have a lower priority for LACP and are most likely to be chosen as active links,
rather than hot-standby links.
LACP administrative key—LACP automatically configures an administrative key value equal to the
channel-group number on each port configured to use LACP. The administrative key defines the
ability of a port to aggregate with other ports. A port's ability to aggregate with other ports is
determined by these factors:
Port physical characteristics, such as the data rate, the duplex capability, and the point-to-point
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or shared medium state
Configuration restrictions that you establish
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describes the channel modes.
Channel Modes for Individual Links in a Port Channel
Description
LACP mode that places a port into a passive negotiating state, in which the port
responds to LACP packets that it receives but does not initiate LACP negotiation.
LACP mode that places a port into an active negotiating state, in which the port
initiates negotiations with other ports by sending LACP packets.
All static port channels, that is, that are not running LACP, remain in this mode.
If you attempt to change the channel mode to active or passive before enabling
LACP, the device returns an error message.
You enable LACP on each channel by configuring the interface in that channel for
the channel mode as either active or passive. When an LACP attempts to negotiate
with an interface in the on state, it does not receive any LACP packets and
becomes an individual link with that interface; it does not join the LACP channel
group.
A port in active mode can form a port channel successfully with another port that is in active mode.
A port in active mode can form a port channel with another port in passive mode.
Chapter 11 Configuring Port Channels
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