[netperf-talk] Netperf over subnet range

[Rick Jones]

Clive Barker wrote:
> Hi all,
> 
> I was wondering if netperf will allow sending packets over a subnet range.
> I intend to create several subinterfaces to simulate client connections 
> on a port.
> Netperf is being used to send packets across each of the interfaces but i
> would like to be able to send traffic across a subnet range to cover all
> interfaces. Is this possible, can anyone advice pls?

Any one instance of netperf, as currently coded, will send traffic to a single 
destination.  If you have multiple logical/sub interfaces on a system each with 
their own IP and you want to ensure that traffic flows across all of them, then 
you can run multiple netperf instances.  If each of the logical/sub interfaces is 
in a separate subnet, then specifying a separate destination (either a global or 
test-specific -H option) in each netperf will usually suffice.  However, if you 
configure each of the logical/sub interfaces into the same subnet you will 
probably want to include a test-specific -L option to tell netperf to bind its 
local socket to a specific IP.

To get your subnet range, you need to have a script wrapping netperf commands - 
netperf itself deals in discrete source/destination specifications.

Depending on your OS you may have to do other things as well to get traffic to 
flow out all the interfaces - even if they are configured in separate subnets. 
Some OS's TCP stacks take a _very_ literal view of the weak end systems model.