[dpdk-users] pktgen - IP address randomness

[Wiles, Keith]

> On May 22, 2017, at 6:31 PM, Chris Hall <chris.hall at stackpath.com> wrote:
> 
> Hello,
> 
> pktgen-3.2.4
> 
> I Looking to get as much randomness out of src ip’s as possible. Using this config in lua…
> 
>        pktgen.src_ip('0', 'start',"0.0.0.1");
>        pktgen.src_ip('0', 'min', "0.0.0.1");
>        pktgen.src_ip('0', 'max', "255.255.255.254");
>        pktgen.src_ip('0', 'inc', "1.1.1.1”);

Currently you can not have a huge number of random values, the reason is to maintain performance levels I initialize the packets before starting the TX and do not update the packets on the fly in range mode.

The other problem I see is incrementing the IP address by 1.1.1.1 would only give about 256 IP address is that right. One other person used the lua scripts to setup N number of IP addresses then stopped, change the range to next N ranges and so on till he was able to test all of the ranges or very close to that many. The number of mbufs allocated to range mode is about 8192 packets, which means processing the packets in groups of 8192.

Not sure how long that will take, but not sure how long it would have taken is the range mode did support the complete range.

> 
> running a packet capture of 5Million packets on the receiving host, parsing the pcap file, based on source ip, seems I can only get about 32769 uniq ip's, (each connected about 150 times).
> 
> As a comparison I used hping3 with --rand-source option (5million packets) I can get about 4942744 uniq ip’s.
> 
> Is there a configure option(s) somewhere that could be tuned for more randomness or is the above parms just wrong ?
> 
> Thanks much.
> 
>  *   Chris
> 
> 
> 

Regards,
Keith