Stateless Traffic Gen with VPP

It’s simple to configure vpp as a high-performance stateless traffic generator. A couple of vpp worker threads running on an older system can easily generate 20 MPPS’ worth of traffic.

In the configurations shown below, we connect a vpp traffic generator and a vpp UUT using two 40 gigabit ethernet ports on each system:

+-------------------+           +-------------------+
| traffic generator |           | UUT               |
| port 0            | <=======> | port 0            |
| 192.168.40.2/24   |           | 192.168.40.1/24   |
+-------------------+           +-------------------+

+-------------------+           +-------------------+
| traffic generator |           | UUT               |
| port 1            | <=======> | port 1            |
| 192.168.41.2/24   |           | 192.168.41.1/24   |
+-------------------+           +-------------------+

Traffic Generator Setup Script

set int ip address FortyGigabitEthernet2/0/0 192.168.40.2/24
set int ip address FortyGigabitEthernet2/0/1 192.168.41.2/24
set int state FortyGigabitEthernet2/0/0 up
set int state FortyGigabitEthernet2/0/1 up

comment { send traffic to the VPP UUT }

packet-generator new {
    name worker0
    worker 0
    limit 0
    rate 1.2e7
    size 128-128
    tx-interface FortyGigabitEthernet2/0/0
    node FortyGigabitEthernet2/0/0-output
    data { IP4: 1.2.40 -> 3cfd.fed0.b6c8
           UDP: 192.168.40.10 -> 192.168.50.10
           UDP: 1234 -> 2345
           incrementing 114
    }
}

packet-generator new {
    name worker1
    worker 1
    limit 0
    rate 1.2e7
    size 128-128
    tx-interface FortyGigabitEthernet2/0/1
    node FortyGigabitEthernet2/0/1-output
    data { IP4: 1.2.4 -> 3cfd.fed0.b6c9
           UDP: 192.168.41.10 -> 192.168.51.10
           UDP: 1234 -> 2345
           incrementing 114
    }
}

comment { delete return traffic on sight }

ip route add 192.168.50.0/24 via drop
ip route add 192.168.51.0/24 via drop

Note 1: the destination MAC addresses shown in the configuration (e.g. 3cfd.fed0.b6c8 and 3cfd.fed0.b6c9) must match the vpp UUT port MAC addresses.

Note 2: this script assumes that /etc/vpp/startup.conf and/or the command-line in use specifies (at least) two worker threads. Uncomment “workers 2” in the cpu configuration section of /etc/vpp/startup.conf:

## Specify a number of workers to be created
## Workers are pinned to N consecutive CPU cores while skipping "skip-cores" CPU core(s)
## and main thread's CPU core
workers 2

Any plausible packet generator script - including one which replays pcap captures - can be used.

UUT Setup Script

The vpp UUT uses a couple of static routes to forward traffic back to the traffic generator:

set int ip address FortyGigabitEthernet2/0/0 192.168.40.1/24
set int ip address FortyGigabitEthernet2/0/1 192.168.41.1/24
set int state FortyGigabitEthernet2/0/0 up
set int state FortyGigabitEthernet2/0/1 up

ip route add 192.168.50.10/32 via 192.168.41.2
ip route add 192.168.51.10/32 via 192.168.40.2