Cisco WS-C6506 Software Manual page 130

Configuring an EtherChannel Using PAgP
The EtherChannel VLAN cost feature provides load balancing of VLAN traffic across multiple channels
that are configured with trunking.
You enter the set spantree channelvlancost command to set the initial spanning-tree costs for all
VLANs in the channel. The set spantree channelvlancost command provides an alternate cost for some
of the VLANs in the channel (assuming that you are trunking across the channel). This command allows
you to have up to two different spanning-tree costs assigned per channel; some VLANs in the channel
can have the "vlancost" while the remaining VLANs in the channel have the "cost."
The set spantree channelvlancost command creates a "set spantree portvlancost" entry to the
configuration file for each port in the channel. After you enter the set spantree channelvlancost
command, you must enter the set spantree portvlancost command for at least one port in the channel,
specifying the VLAN or VLANs that you want associated with each port. This example shows what
occurs when you enter each command:
Console> (enable) set spantree channelvlancost 856 10
Port(s) 3/47-48 vlan cost are updated to 16.
Channel 856 vlancost is set to 10.
These commands are added to the configuration file:
set spantree portvlancost 3/47 cost 16
•
set spantree portvlancost 3/48 cost 16
•
To add the desired VLANs to the above created commands, enter this command:
Console> (enable) set spantree portvlancost 3/47 cost 16 1-1005
Port 3/47 VLANs 1025-4094 have path cost 19.
Port 3/47 VLANs 1-1005 have path cost 16.
Port 3/48 VLANs 1-1005 have path cost 16.
To set the EtherChannel VLAN cost, perform this task in privileged mode:
Task
Step 1
Use the administrative group number to display
the EtherChannel ID.
Step 2 Use the EtherChannel ID to set the EtherChannel
VLAN cost.
Step 3
Configure the port cost for the desired VLANs on
each port.
This example shows how to set the EtherChannel VLAN cost for channel ID 856:
Console> (enable) show channel group 22
Admin Port
group
----- ----- ---------- --------- --------
22
22
Admin Port
group
----- ----- ------------------------------- ------------------------- ----------
22
22
Console> (enable)
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
6-10
Status Channel
Mode
1/1 notconnect on
1/2 connected on
Device-ID
1/1
1/2 066510644(cat26-lnf(NET25))
Command
show channel group admin_group
or
show lacp-channel group admin_key
set spantree channelvlancost channel_id cost
set spantree portvlancost {mod/port} [cost cost]
[vlan_list]
Channel
id
856
856
Port-ID
2/1
Chapter 6 Configuring EtherChannel
Platform
WS-C6009
OL-8978-04