[dpdk-users] pktgen - IP address randomness

[Shyam Shrivastav]

Sometime back I used lua in moongen to continuously generate ip:tcp packets
with random ip src and random tcp src/dst ports. Here is the corresponding
lua script fragment, don't know how much useful it can be with pktgen as I
have not looked at or used pktgen till now but just in case ...


                        x1 = math.random(1,254);
                        x2 = math.random(1,254);
                        x3 = math.random(1,254);
                        x4 = math.random(1,254);
                        p1 = math.random(1025,65534);
                        p2 = math.random(1025,65534);
                        pkt.ip.src:set(x1*256*256*256 + x2*256*256 + x3*256
+ x4)
                        pkt.tcp:setSrcPort(p1);
                        pkt.tcp:setDstPort(p2);




On Tue, May 23, 2017 at 5:01 AM, 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");
>
> 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
>
>
>
>