Re: Specifying interface for iperf
Chris,
I posted a few months back with the same kind of problem -- doing
multicast testing using clients/servers with multiple network interface
cards.
...the problem *can* be solved with mods to iperf, but those may or may
not be in the works...
As an immediate fix for you, you should set up a static route on your
server machine so that the kernel knows to send the join requests to the
proper interface. (Otherwise it just picks the first one on the list,
which in your case is probably the "other one.")
Something like this should work:
route add -net 224.0.0.0 netmask 255.225.0.0 -dev eth1
then any multicast address 224.0.*.* would be "bound" to eth1.
If I recall, this was really only needed on the client side, not the server
side. (i.e. the combination of -i and -B options could be made to do the
right thing on the server side, but not the client side). But it will work
on either side. Search the archives for a posting from me on this topic to
get more details.
Jim
cnelson --at-- nycap.rr.com wrote:
>
> Running iperf 2.0 on a Linux system with 2 interfaces, I do:
>
> iperf -s -u -B 224.0.55.55 -i 1 &
>
> and I see:
>
> Server listening on UDP port 5001
> Binding to local address 224.0.12.34
> Joining multicast group 224.0.12.34
> Receiving 1470 byte datagrams
> UDP buffer size: 64.0 KByte (default)
>
> but I _don't_ see any join message on my network of interest. I'm guessing it went out the other interface. Can I specify the interface to use? I don't see any option for that in the docs.
>
> Thanks.
>
> Chris
--
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James T. Kaba
Sarnoff Corporation There are 10 kinds of people in the world:
jkaba --at-- sarnoff.com those who understand binary, and those who don't.
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