Hey all this is a repost from a question I asked on the cisco forums but never got a useful reply.

Hey I'm trying to convert the FreeBSD servers at work to dual-gig lagg links from regular gigabit links. Our production servers are on a 3560. I have a small test environment on a 3550. I have achieved fail-over, but am having troubles achieving the speed increase. All servers are running gig intel (em) cards. The configs for the servers are:

BSDServer:

#!/bin/sh

#bring up both interfaces
ifconfig em0 up media 1000baseTX mediaopt full-duplex
ifconfig em1 up media 1000baseTX mediaopt full-duplex

#create the lagg interface
ifconfig lagg0 create

#set lagg0's protocol to lacp, add both cards to the interface,
#and assign it em1's ip/netmask
ifconfig lagg0 laggproto lacp laggport em0 laggport em1 ***.***.***.*** netmask 255.255.255.0

The switches are configured as follows:

#clear out old junk
no int Po1
default int range GigabitEthernet 0/15 - 16

# config ports
interface range GigabitEthernet 0/15 - 16
description lagg-test
switchport
duplex full
speed 1000
switchport access vlan 192
spanning-tree portfast
channel-group 1 mode active
channel-protocol lacp
**** switchport trunk encapsulation dot1q ****
no shutdown
exit

interface Port-channel 1
description lagginterface
switchport access vlan 192
exit

port-channel load-balance src-mac
end

obviously change 1000's to 100's and GigabitEthernet to FastEthernet for the 3550's config, as that switch has 100Mbit speed ports.

With this config on the 3550, I get failover and 92Mbits/sec speed on both links, simultaneously, connecting to 2 hosts.(tested with iperf) Success. However this is only with the "switchport trunk encapsulation dot1q" line.

First, I do not understand why I need this, I thought it was only for connecting switches. Is there some other setting which this turns on that is actually responsible for the speed increase? Second,

This config does not work on the 3560. I get failover, but not the speed increase. Speeds drop from gig/sec to 500Mbit/sec when I make 2 simultaneous connections to the server with or without the encapsulation line. I should mention that both switches are using source-mac load balancing.

In my test I am using Iperf. I have the server(lagg box) setup as the server(iperf -s), and the client computers are client(iperf -c server-ip-address), so the source mac(and IP) are different for both connections.

Any ideas/corrections/questions would be helpful, as the gig switches are what I actually need the lagg links on. Ask if you need more information.