Bandwidth issue on switch

[Intelligroup_2]

Hi,

We have a cisco WS-C3560G-24TS switch as a core.

there some servers connected to this switch. When we tested for available bandwidth between 2 servers using a tool "iperf". when ran it multiple times the results varied from 500MB to 700 MB.

These 2 servers have to trasnfer a lot of data between them, and the users working on this find the data tranafer rate slow.

Is there any config that needs to be checked. What all needs to be checked.

Config on port :

interface GigabitEthernet0/11
switchport mode access
storm-control broadcast level 5.00
storm-control multicast level 5.00
spanning-tree portfast
spanning-tree bpdufilter enable
spanning-tree guard root

Thanks

[Ganesh Hariharan]

Check out the duplex setting with 1000 Mb speed at both the end server and switch port end !! If that is ok then connect 2 switch port bundle with server two nic then see the performance.

Regards

Ganesh.H

[Intelligroup_2]

The ports are 1000 full duplex on both switch port and server end.

We are not getting the speed which should be for a 1000 mb port between these 2 servers connected directely on this switch.

[Ganesh Hariharan]

Is any error are you seeing in switch port which are connected to server by issuing command "sh int gigabitEthernet"

Regards

Ganesh.H

[Intelligroup_2]

There are no errors or drops on the interface.

The cables used are CAT6E.

CPU usage is less than 5 %

What is the ideal transfer speed that i should be getting between 2 systems conencted to this switch on a GIG port.

[Ganesh Hariharan]

It is worth noting that you will not get the full bandwidth rating. Expect to lose up to about 20% of your throughput due to overhead. In a 1000 Mbps network this would mean you can expect throughput of about 800 Mpbs.

As stated getting 80% on your 1000 Mbps switch, that as you can see from my calculations is average and the expected amount of bandwidth.

Another suggestion try for bundling of port at switch end means 2:2 connectivity between switch and server end.

Hope this will clear at some extent !!

Regards

Ganesh.H

[Intelligroup_2]

Bundling is a good idea to increase speed.

But is there any thing that I need to check form config point of view, to be able to get that 800Mb of transfer rate on a single Gig port.

Thanks

[Ganesh Hariharan]

No I dont think so you need to do extra configuration in direct server to switch connectivity.

Regards

Ganesh.H