Configure LLA

To configure LLA on a switch, you must first configure the LLA and ISL port-channels.

Connect the host to one port on each of the switches. The connections must be to the same port number on both switches. Form an aggregate on the host with the interfaces connected to these ports. Both active-active and active-standby configurations for aggregate ports are allowed.

On each switch, create the LLA port-channel, ISL port-channel and add the member ports. The LLA port on each switch is the port connected to the host. The ISL ports are the ports connecting the two switches. The LLA port-channel and corresponding member ports must be the same on both switches. Then configure the LLA role as primary or secondary for both switches. Ensure that one switch is the primary and the other the secondary. Then enable LLA. If the enable LLA command is not executed, LLA will not be enabled after restart, even though the LLA role and ports are configured. Then restart the SEFOS on the switches. After the restart, LLA will be operable and the switches will assume their respective roles.

1. Create an LLA port-channel.

   Switch-<n>(config)# interface port-channel 101
    
   The LLA port-channels are reserved from 101 to 124. The mode changes to port-channel configuration.
    
   Switch-<n>(config-if)# no shut 
   Switch-<n>(config-if)# exit 

2. Create the ISL port-channel.

   Switch-<n>(config)# interface port-channel 100
    
   The port-channel 100 is reserved for ISL. The mode changes to port-channel configuration.
    
   Switch-<n>(config-if)# spanning-tree cost 10
    
   The ISL port-channel must be in forwarding state on both the fabrics.
    
   Switch-<n>(config-if)# no shutdown
   Switch-<n>(config-if)# exit

3. Add ports to the LLA port-channel.

   Switch-<n>(config)# interface extreme-ethernet 0/15
   Switch-<n>(config-if)# channel-group 101 mode on
   Switch-<n>(config-if)# no shutdown 
   Switch-<n>(config-if)# exit

4. Add ports to the ISL port-channel.

   Switch-<n>(config)# interface extreme-ethernet 0/11
   Switch-<n>(config-if)# channel-group 100 mode on
   Switch-<n>(config-if)# no shutdown 
   Switch-<n>(config-if)# exit
    
   Switch-<n>(config)# interface extreme-ethernet 0/12
   Switch-<n>(config-if)# channel-group 100 mode on
   Switch-<n>(config-if)# no shutdown
   Switch-<n>(config-if)# exit

   The ISL ports must be contiguous. The interface range command may also be used to add ports to the ISL port-channel.

5. Set the LLA role and add the ISL and LLA port-channels.

   The role is configured as primary on one switch and as secondary on the other switch.

   Switch-1(config)# lla
   Switch-1(config-lla)# role primary
    
   Switch-1(config)# lla
   Switch-2(config-lla)# role secondary
    
   Switch-<n>(config-lla)# isl port-channel 100 
   Switch-<n>(config-lla)# lla port-channel 101
   Switch-<n>(config-lla)# exit
   Switch-<n>(config)#

6. Enable LLA.

   Switch-<n># configure terminal
   Switch-<n>(config)# set lla enable
    
   Switch-<n>(config)# set port-channel enable

   The port-channel feature has to be enabled for LLA.

7. Verify the configuration.

   Switch-1# show lla role 
    
   LLA Role: primary
   Switch-1# show lla status
    
   LLA Disabled with role not set at bootup
    
   SEFOS. LLA configurations take affect only after saving the configuration and restarting 
    
   SEFOS# show lla ports
    
   Isl Trunk Port-channel: port-channel 100
   Ports:
   interface  extreme-ethernet 0/11
   interface  extreme-ethernet 0/12
    
   Lla Port-channel: port-channel 101
   Ports:
   interface  extreme-ethernet 0/15

8. Save the LLA configuration.

   Switch-<n># write startup-config
    
     LLA configuration takes affect after restarting the SEFOS.

9. Verify the configuration by checking connectivity between a host connected to an uplink on one of the switches to another host connected to the LLA ports on both switches.

   Switch-1# show lla status
    
   LLA Enabled with role primary at bootup

   • Ping from Host A on uplink port 10 on switch 1 to Host B on LLA ports 15. On Host B, the interfaces connected to the switches are bonded.

     

     [Host-A ~]# ping host-b
      
     PING host-b (192.168.1.10) 56(84) bytes of data. 
     64 bytes from host-b (192.168.1.10): icmp_seq=0 ttl=255 time=1.61 ms 
     64 bytes from host-b (192.168.1.10): icmp_seq=1 ttl=255 time=0.288 ms 
      
     --- host-b ping statistics --- 
     2 packets transmitted, 2 received, 0% packet loss, time 1002ms 
     rtt min/avg/max/mdev = 0.288/0.952/1.616/0.664 ms

   • Shut down LLA port 15 on switch 1. Traffic resumes in very short time through port 15 on switch 2.

10. Show the running configuration for LLA.

    Switch-1# show running-config LLA
     
    Building configuration...
    lla enabled
    !
    role primary
    !
    interface port-channel 100
    isl trunk port-channel
    !
    interface  extreme-ethernet 0/11
    isl port
    !
    interface  extreme-ethernet 0/12
    isl port
    !
    !
     
    !
    interface port-channel 101
    lla port-channel
    !
    interface  extreme-ethernet 0/15
    lla port
    !
    end