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solaikumar_1217's avatar
solaikumar_1217
Icon for Nimbostratus rankNimbostratus
Jul 31, 2014

One ARM Mode - Port grouping

Dear All,

 

Do you have any idea about port grouping , I understand that it can bundle the multiple ports to increase the bandwidth .

 

But my query here is , incase if we want to connect the grouped ports in different switches which is in sync . how it passes the traffic without LACP.

 

the topology is given below

 

F5-LTM - Portgroup 1 - port 1.1 ----------> connected to switch 1

 

F5-LTM - Portgroup 1 - port 1.2 ----------> connected to switch 2

 

Thank you all in advance...:)

 

application delivery
availability
design
LTM
TMOS
TMSH

6 Replies

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  • mimlo_61970's avatar
    mimlo_61970
    Icon for Cumulonimbus rankCumulonimbus
    Jul 31, 2014

    The above topology would create a loop. Assuming you run spanning-tree on the switches, and the F5 is in the default Pass Through, one of those switches would put the port in a blocking state, effectively leaving you with one active port, and one backup port.

     

    • mimlo_61970's avatar
      mimlo_61970
      Icon for Cumulonimbus rankCumulonimbus
      Aug 01, 2014
      I over simplified in my statement above. There is no guarantee that one of the ports facing the F5 would go blocking. You would need to look at port costs and such to validate that port will go blocking and not another port leading to the root. You can use root-guard on the ports leading to the F5 to make sure they never become a path to the root.
  • Karthik_Kumaran's avatar
    Karthik_Kumaran
    Icon for Nimbostratus rankNimbostratus
    Jan 12, 2016

    you can connect the grouped ports to different upstream switches, if you have switches capable of doing something like Cisco Nexus vPC technology.

     

    • solaikumar_1217's avatar
      solaikumar_1217
      Icon for Nimbostratus rankNimbostratus
      Jan 12, 2016
      Hi Karthik, Thanks for the reply . What's else if we don't have any VPC supported switches. Consider you have back to back trunk between 2 non-nexus switches
  • Karthik_Kumaran's avatar
    Karthik_Kumaran
    Icon for Nimbostratus rankNimbostratus
    Jan 12, 2016

    in that case, like mimlo mentioned, STP may put one of the ports in blocking mode. If you have non-nexus switches there is no way you can bundle ports between those switches. So you cannot make a complete LACP configuration with just having the port-grouping on the F5 side alone.