Understanding Frame Distribution - Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual

Chapter 6 Configuring EtherChannel
Table 6-1
Table 6-1
Mode
on
off
auto
desirable
silent
non-silent Keyword that is used with the auto or desirable mode when traffic is expected from the
Both the auto and desirable modes allow ports to negotiate with connected ports to determine if they
can form an EtherChannel, based on criteria such as port speed, trunking state, and VLAN numbers.
Ports can form an EtherChannel when they are in different PAgP modes as long as the modes are
compatible:
•
•
•

Understanding Frame Distribution

EtherChannel distributes frames across the links in a channel by reducing part of the binary pattern
formed from the addresses in the frame to a numerical value that selects one of the links in the channel.
Enter the show module command for the supervisor engine to determine if EtherChannel frame
distribution is configurable on your switch:
•
•
78-13315-02
describes EtherChannel modes.
EtherChannel Modes
Description
Mode that forces the port to channel without PAgP. With the on mode, a usable
EtherChannel exists only when a port group in on mode is connected to another port group
in on mode.
Mode that prevents the port from channeling.
PAgP mode that places a port into a passive negotiating state, in which the port responds
to PAgP packets it receives but does not initiate PAgP packet negotiation. (Default)
PAgP mode that places a port into an active negotiating state, in which the port initiates
negotiations with other ports by sending PAgP packets.
Keyword that is used with the auto or desirable mode when no traffic is expected from
the other device to prevent the link from being reported to the Spanning Tree Protocol as
down. (Default)
other device.
A port in desirable mode can form an EtherChannel successfully with another port that is in
desirable or auto mode.
A port in auto mode can form an EtherChannel with another port in desirable mode.
A port in auto mode cannot form an EtherChannel with another port that is also in auto mode,
because neither port will initiate negotiation.
If the display shows the "Sub-Type" to be "L2 Switching Engine I WS-F6020," then EtherChannel
frame distribution is not configurable on your switch; it uses source and destination Media Access
Control (MAC) addresses.
EtherChannel frame distribution is configurable with all other switching engines. The default is to
use source and destination IP addresses.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
Understanding How EtherChannel Works
6-3