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jwa999999
Beginner

Help with intepreting Iperf results?

Can someone tell me why you might see a result like this one below?  I'm trying to determine why you would see 4.89 Mbits/sec.

This is a consistent result

I've got the laptops and the server plugged into the same Cisco 3750G switch.

Both laptops have 1 gb nics. Laptops and server have the latest nic drivers.

Server has a pair of nic's, they're not teamed.

When I ran iperf between the laptops I had them plugged into the same ports the server uses.

Based on the results between the laptops, I'm focusing on the servers nics.

I've tried disabling the server's nic's tcp offload features. 

Tested using both nic's in the server.

Tested from the laptop to the server, and from the server to the laptop.

Laptops are running Win7 Pro SP1, Server's running Win2003 Standard.

I've also tried a laptop running WinXP SP3.

None of it has made a difference, I get the same result.

I'm testing throughput between two points, I'm not testing switch capacity.

I've searched the forums using the keyword Iperf, and read the discussions.

I've read that using two laptops and tcp is not the optimal way to test throughput. 

I'll try UDP tomorrow.  Thanks go out to Ricardo's post.

We're a non-profit, so it's Iperf and laptops, can't afford something like Smartbits.

I see this result on more than just the one server.

Thanks

laptop to server

C:\iperf>iperf -c 172.16.16.62 -d

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

------------------------------------------------------------

Client connecting to 172.16.16.62, TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

[  4] local 172.16.16.8 port 51013 connected with 172.16.16.62 port 5001

[  5] local 172.16.16.8 port 5001 connected with 172.16.16.62 port 1833

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0-10.0 sec   813 MBytes   681 Mbits/sec

[  5]  0.0-10.3 sec  6.00 MBytes  4.89 Mbits/sec

C:\iperf>iperf -c 172.16.16.62 -r

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

------------------------------------------------------------

Client connecting to 172.16.16.62, TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

[  4] local 172.16.16.8 port 51075 connected with 172.16.16.62 port 5001

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0-10.0 sec   755 MBytes   632 Mbits/sec

[  4] local 172.16.16.8 port 5001 connected with 172.16.16.62 port 1836

[  4]  0.0-10.4 sec  6.12 MBytes  4.96 Mbits/sec

laptop to laptop

C:\iperf>iperf -c 172.16.16.4 -d

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

------------------------------------------------------------

Client connecting to 172.16.16.4, TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

[  4] local 172.16.16.8 port 49556 connected with 172.16.16.4 port 5001

[  5] local 172.16.16.8 port 5001 connected with 172.16.16.4 port 49250

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0-10.0 sec   446 MBytes   374 Mbits/sec

[  5]  0.0-10.0 sec   375 MBytes   315 Mbits/sec

C:\iperf>iperf -c 172.16.16.4 -r

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

------------------------------------------------------------

Client connecting to 172.16.16.4, TCP port 5001

TCP window size: 64.0 KByte (default)

------------------------------------------------------------

[  4] local 172.16.16.8 port 49654 connected with 172.16.16.4 port 5001

[ ID] Interval       Transfer     Bandwidth

[  4]  0.0-10.0 sec   763 MBytes   640 Mbits/sec

[  4] local 172.16.16.8 port 5001 connected with 172.16.16.4 port 49252

[  4]  0.0-10.1 sec   490 MBytes   406 Mbits/sec

1 REPLY 1
ndiwakar
Cisco Employee

Hi Jim,

Can you execute the commands below and attach the outputs.

- show mls qos

- show interface gi (execute this command on interfaces conneting to the servers and the two laptops)

- show version

Thanks,

Ninad