@MHM Cisco World makes an interesting point about the SDM template. Can we get some clarification about the SDM setting of both 3750 switches?
The original poster tells us that "the traffic is 2G because I have a portchannel". That is probably mistaken logic. The primary advantage of port channel is redundancy (sending traffic over a different interface is an interface stops working) and not necessarily aggregate bandwidth. The port channel chooses which interface to use to forward a frame based its evaluation of several parameters. It is quite possible that for the PBR traffic it might use the same outbound interface for all of the PBR traffic.
When I look at a post that says that traffic between hosts is slower than expected I wonder about the possibility of mismatch between interfaces of the connected devices. Especially the possibility of mismatch of duplex between peers (half duplex on one but full duplex on the other). Is that possibly the case here?
The other aspect of this question that I wonder about is the forwarding rate of the interfaces. The assumption that a 1 Gig interface can forward at 1 G rate is based on the assumption that the switch is making forwarding decision in hardware and that the switch hardware is non blocking. I wonder if that assumption is true on this switch? I especially wonder if PBR on this switch is not done on the interface but is punted to the CPU for processing. There is a major impact on through put when the forwarding is CPU based rather than hardware based.
HTH
Rick
