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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 27 Configuring Eth erChannels Configuring EtherChannels
Beginning in privileged EXEC mode, follow these steps to assign a Layer 2 Ethernet interface to a
Layer 2 EtherC hannel :
Command Purpose
Step 1 configure terminal Enter globa l configurati on mode.
Step 2 interface interface-id Enter interface configuration mode, and specify a physical
interface to configure.
Valid i nte rfac es i ncl ude physi cal inter faces.
Up to eight interfaces of the same type and speed can be
configured fo r the sam e group.
Step 3 channel-group channel-group-number mode
{auto [non-silent] | desirable [ non-silent] | on}Assign the interface to a channel group, and specify the PAgP
mode. The default mode is auto silent.
For channel-group-number, the range is 1 to 6. Each
EtherCh annel can have of up to eigh t compat ibly configur ed
Ethe rnet inte rfa ces.
For mode, se le ct one o f these keywords:
•auto—Enables PAgP only if a PAgP device is detected. It
places an in ter f a ce in to a pa ssive nego tiat i ng stat e, in which
the interface responds to PAgP packets it receives but does
not start PAgP packet negotiatio n.
•desirable—Unconditionally enables PAgP. It places an
interface into an active neg otiating state, in which the
interface starts negotiations with other interfaces by sending
PAgP packets.
•on—Forces the interface to channel without PAgP. With the
on mode , a us able E the rChan ne l exis ts on ly whe n an
inte rfa ce gr ou p in th e on mode is connec ted to an other
inte rfa ce gr ou p in th e on m ode.
•non-silent—If your switch is connected to a partner that is
PA gP-ca pa ble, y ou ca n c onfigure th e sw itch in te rface fo r
nonsilent operation. You can configure an interface with the
non-silent ke yword for use with the auto or desirable mode.
If you do not specify non-silent with the auto or desirable
mode, silent is assumed. The silent setting is for conne ctions
to file servers or packet analyzers; this setting allows PAgP
to operate, to attach the interface to a channel group, and to
use the interface for transmission.
For information on compatible PAgP modes for the switch and its
partne r, see the “PAgP Modes” section on page 27-4.
Step 4 end Return to privileged EXEC mode.
Step 5 show running-config Verify your e ntrie s.
Step 6 copy running-config startup-config (Optiona l) Save your entries in the co nfigurati on file.