ETHER-CHANNEL

ETHER-CHANNEL

Bundle the interfaces between switches. 

No loop Formation, Redundant, Increase the Bandwidth.Automatic Load 

balance. (Load balance based on source mac or designation mac address).

Only Similar Link can Bundle.

Example: Trunk links means only the trunk links, Access links means only the 

access links.Trunk link and access link can not be bundle.

Bundled interfaces, one interface go down, it own effect Ether- channel, but 

port-channel goes down effect the ether channel.

Ether-CHANNEL channel cannot be configured in SPAN port (Monitor Port).

Bundled view as a one logical port (PO1) , Cost also it will reduce from 19 to 12.

All the Interfaces are same speed and duplex. Cost may be differ.

Round robin method is using.

Two Aggregation Protocol - LACP and PAgp

1. LACP  - Link Aggregation Protocol - Industry standard. - 16 ports can bundle. 

    Modes: On, Active, Passive. 

    Note: for Negotiation one side Active and other side Passive.

2. PAgP  - Port Aggregation Protocol - cisco proprietary. - 8 ports can bundle. 

    Modes: On, Auto, Desirable.

    Note: for Negotiation one side Auto and other side Desirable.

Ether-Channel will support Layer 2 (Switch mode) & Layer 3 (Router Mode).

LAYER 2 Configuration Part:

Channel-group <group no> mode <mode>

Channel-protocol <protocol>

Interface range f0/1 - 2

Switch-port mode access

Switch-port access VLAN 3

Show Commands:

Show spanning-tree

Show Ether channel 1 port-channel

Show Ether channel 1 summary

Show Ether channel summary

Show Ether channel port-channel

LAYER 3 Configuration Part: (router mode)

Interface port-channel <No>

no Switch-port

Ip address 10.1.1.1 255.255.255.0

IP routing

Interface range f0/1 - 2

Channel-group <group no> mode <mode>

Automatically detect protocol while above mode selection itself.

Channel-protocol <protocol>

Show Commands for verification:

Show Spanning-tree - it wont work because its in router mode.

Show ip route

port-channel load-balance ?

SW2# show ether-channel summary

Flags: D - down P - in port-channel
I - stand-alone s - suspended
H - Hot-standby (LACP only)
R - Layer3 S - Layer2
U - in use f - failed to allocate aggregation
u - unsuitable for bundling
w - waiting to be aggregated
d - default port

Number of channel-groups in use: 1
Number of aggregators: 1

Group             Port-channel                 Protocol            Ports
------+-------------+-----------+------------------------------------------------------------
1                         Po1(RU)                    PAgP           Fa0/1(P) Fa0/2(P)

SW1#show ether-channel port-channel

Channel-group listing:
----------------------
Group: 1
----------
Port-channels in the group:
---------------------------
Port-channel: Po1
------------
Age of the Port-channel = 00d:00h:08m:24s
Logical slot/port = 2/1 Number of ports = 2
GC = 0x00000000 HotStandBy port = null
Port state = Port-channel
Protocol = PAGP
Port Security = Disabled

Ports in the Port-channel:

Index Load Port EC state No of bits
------+------+------+------------------+-----------
0 00 Fa0/2 Active 0
0 00 Fa0/1 Active 0
Time since last port bundled: 00d:00h:04m:32s Fa0/1