How to test the throughput/performance of your network using Netperf - Part 1

In this multi-part series, I will explain how to use GNU tools and Linux to have a free network throughput test setup. In Part 1 of the series we will use only one NIC to create single unicast TCP/UDP stream to saturate the linkspeed.
First of all what I used to have this test setup (you can adapt it to your needs)

HW :
- 2 HP Blade on same enclosure chassis with 10Gig HP Flex NICs. (servers)
- HP VC Flex 10 (the network device)

Software :- Centos 5.4 x64
- I only installed core GNU packages + development libraries. No unnecessary service/software loaded. Even I took XWindow(Gnome/KDE) out of the package and run the system in rulevel 3.
- Disable Firewall/SELinux
- netperf rpm (ftp://ftp.netperf.org/netperf/netperf-2.4.5.tar.gz)

I made the first run of the test using single Vnet (counterpart of VLANs in HP Virtual Connect). You can also use the same tools to create a setup that utilize Shared Uplink Sets (trunk links on VC). In order to set this up create a Vnet for your load VLAN(Vnet_LOAD). Create the profiles for the blades and assign one FlexNIC with 100Mb to management VNet and the other one to VNet_LOAD (10Gb)

Netperf is based on client server model. After installing the software on both blades you execute different processes on different nodes. netserver as the name states is the server part of the test suite. You can also use the

[root@SERVER ~]# netserver
Starting netserver at port 12865
Starting netserver at hostname 0.0.0.0 port 12865 and family AF_UNSPEC

while netperf is the tool that executes the test and gives output.

[root@CLIENT ~]# netperf -H SERVER -l 15
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to SERVER (*******) port 0 AF_INET
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec
 87380  16384  16384    15.00    9387.92

The default test is TCP_STREAM you can also define other tests like UDP Request Response to fully saturate Full Duplex Link :

[root@CLIENT ~]# netperf -t UDP_RR -H SERVER -l 15

UDP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to SERVER (*********) port 0 AF_INET

Local /Remote

Socket Size   Request  Resp.   Elapsed  Trans.

Send   Recv   Size     Size    Time     Rate

bytes  Bytes  bytes    bytes   secs.    per sec

129024 129024 1        1       15.00    21045.72

Also you can fetch the CPU utilization info while doing the test using -c (local) and -C(remote) parameters

[root@CLIENT ~]# netperf -t UDP_RR -H SERVER -l 15 -c -C

UDP REQUEST/RESPONSE TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to SERVER (*******) port 0 AF_INET

Local /Remote

Socket Size   Request Resp.  Elapsed Trans.   CPU    CPU    S.dem   S.dem

Send   Recv   Size    Size   Time    Rate     local  remote local   remote

bytes  bytes  bytes   bytes  secs.   per sec  % S    % S    us/Tr   us/Tr

129024 129024 1       1      15.00   20964.03   2.06   2.03   15.759  15.481

For detailed documentation and command line options you can check :

http://www.netperf.org/netperf/training/Netperf.html#0.2.2Z141Z1.SUJSTF.8R2DBD.J

On the next parts of the series I will focus on different types of throughput/load tests like multi flow & multi IP throughput testing using netperf & some Linux tweaking and IP multicast testing using MGEN.