Is this Linux? If yes try enabling arp_filter. I suspect iperf binds to an address, not to an interface.
http://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt arp_filter - BOOLEAN 1 - Allows you to have multiple network interfaces on the same subnet, and have the ARPs for each interface be answered based on whether or not the kernel would route a packet from the ARP'd IP out that interface (therefore you must use source based routing for this to work). In other words it allows control of which cards (usually 1) will respond to an arp request. 0 - (default) The kernel can respond to arp requests with addresses from other interfaces. This may seem wrong but it usually makes sense, because it increases the chance of successful communication. IP addresses are owned by the complete host on Linux, not by particular interfaces. Only for more complex setups like load- balancing, does this behaviour cause problems. arp_filter for the interface will be enabled if at least one of conf/{all,interface}/arp_filter is set to TRUE, it will be disabled otherwise 2012/4/17 Andrew M <and...@oc384.net> > > I have two network interfaces in one host: > em1 192.168.123.1 > em2 192.168.234.1 > > I'm running: > > SERVER: > [root@scooby ~]# iperf -fm -p 777 -B192.168.123.1 -s > ------------------------------------------------------------ > Server listening on TCP port 777 > Binding to local address 192.168.123.1 > TCP window size: 0.08 MByte (default) > ------------------------------------------------------------ > [ 4] local 192.168.123.1 port 777 connected with 192.168.234.1 port 777 > [ ID] Interval Transfer Bandwidth > [ 4] 0.0-10.0 sec 24396 MBytes 20444 Mbits/sec > [ 5] local 192.168.123.1 port 777 connected with 192.168.234.1 port 777 > [ 5] 0.0-10.0 sec 20761 MBytes 17410 Mbits/sec > > CLIENT: > [root@scooby ~]# iperf -p 777 -B192.168.234.1 -c192.168.123.1 > ------------------------------------------------------------ > Client connecting to 192.168.123.1, TCP port 777 > Binding to local address 192.168.234.1 > TCP window size: 169 KByte (default) > ------------------------------------------------------------ > [ 3] local 192.168.234.1 port 777 connected with 192.168.123.1 port 777 > [ ID] Interval Transfer Bandwidth > [ 3] 0.0-10.0 sec 20.3 GBytes 17.4 Gbits/sec > > This works even with the cable unplugged so I know it's not using the > ports. Some reason why the client isn't initiating the outbound > connecting on the port it's binding to? > > Thanks, > Andrew > > > > > > > ------------------------------------------------------------------------------ > Better than sec? Nothing is better than sec when it comes to > monitoring Big Data applications. Try Boundary one-second > resolution app monitoring today. Free. > http://p.sf.net/sfu/Boundary-dev2dev > _______________________________________________ > Iperf-users mailing list > Iperf-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/iperf-users ------------------------------------------------------------------------------ Better than sec? Nothing is better than sec when it comes to monitoring Big Data applications. Try Boundary one-second resolution app monitoring today. Free. http://p.sf.net/sfu/Boundary-dev2dev _______________________________________________ Iperf-users mailing list Iperf-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/iperf-users
