Link Aggregation with LACP limited to 50% network utilization

Posted on 2012-08-27
Last Modified: 2016-01-08

I have a Dell R410 server with a NIC Broadcom BCM5716C Nextreme II GigE with 4 ports
Two ports are connected to a CISCO SFE2010 (48p 10/100 with LACP, LAG support).

I want to make a link aggregation on the two ports to make a 200mbps link  (100+100).

First, I created in Cisco, a LAG group with the two ports and activated the LACP with the same priority number.

Than I used the software Broadcom Advanced Control Suite 4 (BACS) to create a team using the LACP procol (802.3ad). The software created a new nework adapter "TEAM 1 - BASP VIRTUAL ADAPTER). The Link Speed that is appearing on Task Manager is 200mbps.

The problem is that when I transfer files to this server, every time the network utilization show me 45~50% and never above this on task manager. What I am doing wrong?

Thank you.
Question by:abracad
    LVL 42

    Accepted Solution

    LACP is session based so if you have a session between 2 nodes (IP to IP) it will not leave the physical nic.  If you have multiple sessions it will split them up between the physical nics.  Think of it as if you have a one to one connection you will not exceed a physical nic.  If you have a many to one connection then you will see it using both physical nics on the LACP
    LVL 2

    Expert Comment

    Working as intended. There is no way to get 200 mbps in one session.

    Author Comment

    If I understood, it´s not possible to increase the throughput with link aggregation ?!?
    It just act like a load balance between the two ports?

    Or there is a way to set to multsession connections to better use the 200Mbps?

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