EtherChannel technology allows us to bundle multiple physical links into one logical link. It is used to increase the bandwidth and provide redundancy between multiple layer 2 / layer 3 interfaces. Layer 2 EtherChannel operates on the data link layer, but layer 3 EtherChannel operates at the network layer, allowing it to route traffic. Ether-channel load balances traffic over all the links in the bundle. We can use a maximum 8 physical interfaces to configure the bundle into a single logical link.
Note:- when we configure the port channel (layer 3) we must configure No switchport command before using the command port-channel. if we do not configure no switchport command. the port channel will be the default layer 2 channel and we can not change it. To avoid this, configure no switchport command.
let's see the configuration of layer 3 EtherChannel:-
Topology:-
Goal: configure layer 3 port-channel verify with show commands and configure routing verify with ping.
- configure the topology as per the diagram
- configure the IP addresses as per the topology
- configure portchannel
- verify port-channel
- configure routing EIGRP
- configure IP on VLAN 1
- verify with show commands.
- ping
IOU1(config-if-range)#no switchport
Creating a port-channel interface Port-channel 10
IOU1(config-if-range)#exit
IOU1(config)#interface port-channel 10
IOU1(config-if)#ip address 192.168.10.1 255.255.255.0
IOU1(config-if)#no shutdown
IOU1(config-if)#exit
IOU2(config-if-range)#no switchport
IOU2(config-if-range)#channel-group 10 mode on
Creating a port-channel interface Port-channel 10
IOU2(config)#interface port-channel 10
IOU2(config-if)#no shutdown
IOU2(config-if)#exit
Channel-group listing:
----------------------
----------
Port-channels in the group:
---------------------------
------------
Logical slot/port = 16/0 Number of ports = 4
GC = 0x00000000 HotStandBy port = null
Passive port list = Et0/0 Et0/1 Et0/2 Et0/3
Port state = Port-channel L3-Ag Ag-Inuse
Protocol = -
Port security = Disabled
------+------+------+------------------+-----------
0 00 Et0/0 On 0
0 00 Et0/1 On 0
0 00 Et0/2 On 0
0 00 Et0/3 On 0
Channel-group listing:
----------------------
----------
Group state = L3
Ports: 4 Maxports = 4
Port-channels: 1 Max Port-channels = 1
Protocol: -
Minimum Links: 0
IOU1(config)#router eigrp 100
IOU1(config-router)#network 10.0.0.0
IOU1(config-router)#network 192.168.10.0
IOU1(config-router)#no auto-summary
IOU1(config-router)#exit
IOU2(config-router)#network 20.0.0.0
IOU2(config-router)#network 192.168.10.0
IOU2(config-router)#no auto-summary
IOU2(config-router)#exit
%DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.10.1 (Port-channel10) is up: new adjacency
%DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.10.2 (Port-channel10) is
up: new adjacency
IOU1(config-if)#switchport
IOU1(config-if)#switchport mode access
IOU1(config-if)#switchport access vlan 1
IOU1(config-if)#exit
IOU1(config-if)#ip address 10.1.1.1 255.0.0.0
IOU1(config-if)#no shutdown
IOU1(config-if)#exit
IOU2(config-if)#switchport
IOU2(config-if)#switchport mode access
IOU2(config-if)#switchport access vlan 1
IOU2(config-if)#exit
IOU2(config-if)#ip address 20.1.1.1 255.0.0.0
IOU2(config-if)#exit
%LINK-3-UPDOWN: Interface Vlan1, changed state to up
\%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.1, timeout is 2 seconds:
Packet sent with a source address of 20.1.1.1
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/6 ms
Type escape sequence to abort.
Tracing the route to 10.1.1.1
VRF info: (vrf in name/id, vrf out name/id)
1 192.168.10.1 1 msec 5 msec 0 msec
