Displaying Etherchannel, Pagp, And Lacp Status; Understanding Layer 2 Trunk Failover - Cisco 3020 - Catalyst Blade Switch Configuration Manual

Chapter 28 Configuring EtherChannels and Layer 2 Trunk Failover

Displaying EtherChannel, PAgP, and LACP Status

To display EtherChannel, PAgP, and LACP status information, use the privileged EXEC commands
described in
Table 28-4 Commands for Displaying EtherChannel, PAgP , and LACP Status
Command
show etherchannel [channel-group-number {detail |
port | port-channel | protocol | summary}] {detail |
load-balance | port | port-channel | protocol |
summary}
show pagp [channel-group-number] {counters |
internal | neighbor}
show lacp [channel-group-number] {counters |
internal | neighbor}
You can clear PAgP channel-group information and traffic counters by using the clear pagp
{channel-group-number counters | counters} privileged EXEC command.
You can clear LACP channel-group information and traffic counters by using the clear lacp
{channel-group-number counters | counters} privileged EXEC command.
For detailed information about the fields in the displays, see the command reference for this release.

Understanding Layer 2 Trunk Failover

Layer 2 trunk failover, also known as link-state tracking, is a feature that provides Layer 2 redundancy
in the network when used with server NIC adapter teaming. When the server network adapters are
configured in a primary or secondary relationship known as teaming, if the link is lost on the primary
interface, connectivity is transparently switched to the secondary interface.
When you enable Layer 2 trunk failover on the switch, the link state of the internal downstream ports are
bound to the link state of one or more of the external upstream ports. An internal downstream port is an
interface that is connected to the server. An external upstream port is an interface that is connected to
the external network. When you associate a set of downstream ports to a set of upstream ports, if all of
the upstream ports become unavailable, trunk failover automatically puts all of the associated
downstream ports in an error-disabled state. This causes the server primary interface to failover to the
secondary interface.
When Layer 2 trunk failover is not enabled, if the upstream interfaces lose connectivity, (the external
switch or router goes down, the cables are disconnected, or link is lost), the link state of the downstream
interfaces remain unchanged. The server is not aware that external connectivity has been lost and does
not failover to the secondary interface.
An interface can be an aggregation of ports (an EtherChannel), or a single physical port in access or trunk
mode. Each downstream interface can be associated with one or more upstream interfaces. Upstream
interfaces can be bundled together, and each downstream interface can be associated with a single group
consisting of multiple upstream interfaces. These groups are referred to as link-state groups.
OL-8915-01
Table 28-4:
Description
Displays EtherChannel information in a brief, detailed, and
one-line summary form. Also displays the load-balance or
frame-distribution scheme, port, port-channel, and protocol
information.
Displays PAgP information such as traffic information, the
internal PAgP configuration, and neighbor information.
Displays LACP information such as traffic information, the
internal LACP configuration, and neighbor information.
Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide
Displaying EtherChannel, PAgP, and LACP Status
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