CCNA Complete Guide 2nd Edition.pdf - Cisco Learning Home

EtherChannel Configuration
- In this section, both the trunks between SW1 and SW2 are configured as an EtherChannel.
- The channel-group [channel-group-number] mode on interface subcommand configures an
interface as an EtherChannel interface and assigns it to an EtherChannel channel group.
- Below shows the other 2 EtherChannel modes that allow a switch to automatically negotiate
with its neighboring switch in establishing an EtherChannel.
auto If configured on both switch ports, an EtherChannel will never be established.
desirable As long as one of the switch ports is configured with this mode, an EtherChannel
will be established.
- EtherChannel configuration on SW2:
SW2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
SW2(config)#int fa0/1
SW2(config-if)#channel-group 1 mode on
SW2(config-if)#
00:40:00: %LINK-3-UPDOWN: Interface Port-channel1, changed state to up
00:40:01: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1,
changed state to up
SW2(config-if)#int fa0/2
SW2(config-if)#channel-group 1 mode on
SW2(config-if)#^Z
SW2#sh spanning-tree
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 24577
Address bbbb.bbbb.bbbb
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 24577 (priority 24576 sys-id-ext 1)
Address bbbb.bbbb.bbbb
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 15
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- -------------------------------
Po1 Desg FWD 12 128.65 P2p
SW2#sh etherchannel 1 summary
Flags: D - down P - in port-channel
I - stand-alone s - suspended
R - Layer3 S - Layer2
u - unsuitable for bundling
U – port-channel in use
d - default port
Group Port-channel Protocol Ports
------+-------------+-----------+-------------------------------------------
1 Po1(SU) - Fa0/1(P) Fa0/2(P)
SW2#
49
Copyright © 2008 Yap Chin Hoong
yapchinhoong@hotmail.com