etherchneel-configuration

etherchneel-configuration

In this blog we are going discuss about to etherchannel configuration

When configuring EtherChannel channel, recall the below points it can very helpful in the configuration of Etherchannel by avoiding the mistakes.

•             You can configure up to eight ports, and remember that ports must be a similar kind (FastEthernet, Gigabit Ethernet).

•             Set all ports to work at a similar Speed and Duplex settings.

•             make sure that all ports are in the enabled mode

•             Switchport settings from the primary port in EtherChannel are duplicated to every single other port in the EtherChannel when the ports are added to the channel group. This is a duplicate activity and not a connection, if you change the settings sometime later, you have to change the settings on all ports. The settings that must same across all ports are

  • Allowed VLAN list
  • STP path cost
  • STP port priority
  • STP PortFast settings
  • EtherChannel groups

Configuration of Eherchannel

To configure Etherchannel, follow the steps shown

etherchannel configuration,
Configuring Etherchannel

Verify the port status before and after configuring the Etherchannel. 

Switch(config)#interface range fa0/1-3 Switch (config-if-range) #switchport mode trunk
Switch(config-if-range)#
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down

%LINEPROTO-5-UPDOWN: Line protocol on interface FastEthernet0/1, changed state to up  
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to up   %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, Changed state to up

Switch(config-if-range)#switchport trunk allowed Vlan all Switch(config -if-range) # 

Verify the  port status after configuration

Switch(config)#interface range fa0/1- 3 Switch(config-if-range)#channel-group ?
     <1-6> Channel group number’ Switch(config-if-range)#channel-group 1 ? 
     mode Etherchannel Mode of the interface ‘ Switch(config-if-range)#channel-group 1 mode ? 
    active          Enable LACP unconditionally 
    auto           Enable PAgP only if a PAgP device is detected  
  desirable     Enable PAgP unconditionally
    on                Enable Etherchannel only 
    passive        Enable LACP only if a LACP device is detected
Switch(config-if-range)#channel-group 1 mode desirable 
Switch(config-if-range)#  Creating a port-channel interface Port-channel 1

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to down
%LINEPROTO‘5’UPDOWN’ Line protocol on Interface FastEthernet0/1; changed State to up
%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/2 Changed State to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2 changed state to up

       Illustration for verification of port status after configuration

Next, configure trunk on fastethernet 0/1 -3.

switch#config t
Enter configuration commands, one per line. End with CNTL/z.
Switch (confjg)interface range fa0/1-3 
Switch (config-if-range) #switchport mode trunk
Switch (config-if-range) #
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/ 1, changed state to down

%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/ 1, Changed state to up 
%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to down
%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to up
%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state to down
%LINEPROTO-S-UPDOWN: Line protocol on Interface FastEthernet0/3, Changed state to up
switch(config-if-range)#switchport trunk allowed vlan all 

                    Illustration for Configuring Trunk on Fastethernet

In SW2: 

Switch#config t
Enter configuration commands, one per line. End with CNTL/Z. Switch(config)#interface range fa0/1-3 
Switch (config-if-range) #exit 
Switch (config) # 
Switch (config) #host SW2 
SW2 (config) # 
SW2(config)#interface range fa0/1- 3 SW2(config-if-range)#channel-group 1 mode auto
SW2 (config-if-range) #
Creating a port-channel interface Port-channel 1

%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/ 1, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/ 1, changed state to up
%LINEPROTO-5-UPDOWN:  Line protocol on Interface FastEthernet0/ 2, changed state to down  
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/2, changed state to up 

                                    Illustration for Configuring in SW2

Optionally, configure and allow VLANs through the port-channel. 

Switch#conf t  Enter configuration commands, one per line. End with CNTL/z.
Switch(config) #interface port-channel 1 Switch(config-if)#switchport trunk allowed vlan 1,2,3 

Illustration for Configuring and Allowing VLANs through Port Channel

Observe that after completion of the Etherchannel configuration in both the switches all three ports are up and in the forwarding state.

Switch#show etherchannel summary 
 Flags: D  –   down                  P –  in port-Channel’ 
            I   –   stand-alone      s  –   suspended 
            H  –   Hot-standby (LACP only) 
            R   –   Layer3               S –   Layer2 t 
            U   –   in use                f   –   failed to allocate aggregator
            u    –   unsuitable for bundling 
            w   –   waiting to be aggregated 
             d   –   default port    Number of channel-groups in use: 1 Number of aggregators: 1

                     Illustration for Summary of Etherchannel

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