Select random source addresses from a CIDR

[Lars Ekman]

I have a problem when all connections/packets belongs to the same "flow" and are routed to the same core (and target on multi-path routing (ECMP)). In my current case one core gets all traffic, even with "-P8", and gets overloaded.

There is a "trick" by assigning a range to the loopback interface described here (and other places);

https://github.com/Nordix/mconnect#many-source-addresses

I would like a "--srccidr" option also in iperf2.

Best Regards,
Lars Ekman

FYI; My project is still a WIP and the problem is described here https://github.com/Nordix/nfqueue-loadbalancer/blob/master/test/README.md#parallel-and-multi-queue

[Robert McMahon]

what part of the ip quintuple is giving uniqueness such that the parallels get bound to different cores? The source port will be unique with -P > 1

[Lars Ekman]

The source address. This is a test outer-source -> loadbalancer VIP. The source port can't be used if packets are fragmented and is apparently not used for NFQUEUE --queue-balance. There may also be network elements in between that does not include ports, even if that is not the problem in my case.

[Robert McMahon]

Does an increment option work, i.e. -B 192.168.1.2 -P 8 --incr-srcip would use .2 thru .9?

[Lars Ekman]

Yes, that should work fine.

[Lars Ekman]

I have now cloned an built locally and I'll be happy to test if you could implement something like this. From a branch or a patch will work fine.

[Robert McMahon]

This is done as described in ticket 112 Please do test and let me know your thoughts. It's in the 2-1-1-dev branch

[Lars Ekman]

Thanks a lot! I will try to get time to test is today, but Monday at the latest.