EtherChannel - Slower than expected

[toprock1970]

Hi guys,

I have an Etherchannel with 2 x 1GB links which seems to be perfroming much slower than expected.

We have a switch stack ( 9 x 3750E-48PD running 15.0(1)SE2) that has a 2 port Etherchannel. These ports connect to a pair of 1GB LAN extensions that break out in our DR site and connect into a pair 3750G-24PS switches (running 12.2(25)SEE4).

I'm having complaints from some of our admins that they are trying to copy some large files across this link and a typical 3GB file is taking over 36 hours - at the weekend when we'd expect much lower traffic.

The config pertaining to the link at the main site is as follows:
interface GigabitEthernet5/0/49
  switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk
 mls qos trust cos
 channel-group 5 mode on

interface GigabitEthernet6/0/49
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk
 mls qos trust cos
 channel-group 5 mode on

interface Port-channel5
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk
 

The config at the other side is:

interface GigabitEthernet1/0/26
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk
 mls qos trust cos
 channel-group 5 mode on

interface GigabitEthernet2/0/25
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk
 mls qos trust cos
 channel-group 5 mode on

interface Port-channel5
 switchport trunk encapsulation dot1q
 switchport trunk native vlan 101
 switchport mode trunk

Do you see any issues with this config?
 

Thanks

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Is your selected load balancing algorithm optimal for your traffic?

All the 3750 series are a bit infamous for high drop rates with bursty traffic especially if QoS is enabled.  What's your drop counters look like?  Is QoS enabled?

BTW, that's a pretty old IOS for your 3750Gs.