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I have been struggling with an LACP implementation for a while now, and the number of variables has really been getting overwhelming.

Right now the setup I have is two hosts running 2008R2, each of which are connected to a Force10 S50 switch.

On the switch I believe LACP is setup correctly and dynamically.

Using the advanced Intel drivers, I have dynamic aggregation set on both hosts. Each host has a Pro/1000 PT LP NIC attached and I am aggregating 2 1gig lines.

The problem arises when transferring test files. Task manager shows a maximum 49% use of the 2gbps teamed line.

What could be causing this behavior?

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That's normal. With a single stream of data over an LACP bond, only 1 connection will be used.

LACP is useful when you have multiple data streams traversing the link and for active/active connection redundancy. Try copying multiple large files to/from different destinations and the utilization should reach close to 100% if it is configured correctly.

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+1 - exactly what I had started to write. :) – EEAA Jun 14 '12 at 16:17
Are data streams TCP connections, or are the src mac, dst mac tuples? – becomingwisest Jun 14 '12 at 16:19
I suppose that depends on how the switch is configured. – MDMarra Jun 14 '12 at 16:23
Thanks very much. When you say to/from different destinations, do you mean different physical hosts. I would like to avoid that if possible due to the extra equipment necessary. – user124712 Jun 14 '12 at 17:36
Depends on how you have your switch configured. If you have it set to use source/destination MAC hash, then you'll need separate machines. If you have it set to use IP/Port hash, then separate, simultaneous transfers from a single host will work, assuming the rest of the hardware on that host is capable of saturating a 2Gb pipe. – MDMarra Jun 14 '12 at 17:44

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