Using VPP with TRex

In this example we use only two systems, csp2s22c03 and net2s22c05, to run TRex VPP is installed on csp2s22c03 and run as a packet forwarding engine. On net2s22c05, TRex is used to generate both client and server-side traffic. TRex is a high-performance traffic generator. It leverages DPDK and run in user space. Figure 2 illustrates this configuration.

VPP is set up on csp2s22c03 exactly as it was in the previous example. Only the setup on net2s22c05 is modified slightly to run TRex preconfigured traffic files.


Figure 2: The TRex traffic generator sends packages to the host that has VPP running.

First we install TRex.

NET2S22C05$ wget --no-cache
NET2S22C05$ tar -xzvf latest
NET2S22C05$ cd v2.37

Then show the devices we have.

NET2S22C05$ sudo ./ -s

Network devices using DPDK-compatible driver
0000:87:00.0 'Ethernet Controller XL710 for 40GbE QSFP+' drv=vfio-pci unused=i40e
0000:87:00.1 'Ethernet Controller XL710 for 40GbE QSFP+' drv=vfio-pci unused=i40e

Network devices using kernel driver
0000:03:00.0 'Ethernet Controller 10-Gigabit X540-AT2' if=enp3s0f0 drv=ixgbe unused=vfio-pci *Active*
0000:03:00.1 'Ethernet Controller 10-Gigabit X540-AT2' if=enp3s0f1 drv=ixgbe unused=vfio-pci
0000:81:00.0 '82599 10 Gigabit TN Network Connection' if=ens787f0 drv=ixgbe unused=vfio-pci
0000:81:00.1 '82599 10 Gigabit TN Network Connection' if=ens787f1 drv=ixgbe unused=vfio-pci

Other network devices

Create the /etc/trex_cfg.yaml configuration file. In this configuration file, the port should match the interfaces available in the target system, which is net2s22c05 in our example. The IP addresses correspond to Figure 2. For more information on the configuration file, please refer to the TRex Manual.

NET2S22C05$ cat /etc/trex_cfg.yaml
- port_limit: 2
  version: 2
  interfaces: ['87:00.0', '87:00.1']
  port_bandwidth_gb: 40
      - ip:
      - ip:

Stop the previous VPP session and start it again in order to add a route for new IP addresses and, according to Figure 2. Those IP addresses are needed because TRex generates packets that use these addresses. Refer to the TRex Manual for details on these traffic templates.

csp2s22c03$ sudo service vpp stop
csp2s22c03$ sudo service vpp start
csp2s22c03$ sudo vppctl
    _______    _        _   _____  ___
 __/ __/ _ \  (_)__    | | / / _ \/ _ \
 _/ _// // / / / _ \   | |/ / ___/ ___/
 /_/ /____(_)_/\___/   |___/_/  /_/

vpp# sho int
              Name               Idx       State          Counter          Count
FortyGigabitEthernet82/0/0        1        down
FortyGigabitEthernet82/0/1        2        down
local0                            0        down

vpp# set interface ip address FortyGigabitEthernet82/0/0
vpp# set interface ip address FortyGigabitEthernet82/0/1
vpp# set interface state FortyGigabitEthernet82/0/0 up
vpp# set interface state FortyGigabitEthernet82/0/1 up
vpp# ip route add via
vpp# ip route add via
vpp# clear run

Now, you can generate a simple traffic flow from net2s22c05 using the traffic configuration file “cap2/dns.yaml”.

NET2S22C05$ sudo ./t-rex-64 -f cap2/dns.yaml -d 1 -l 1000
 summary stats
 Total-pkt-drop       : 0 pkts
 Total-tx-bytes       : 166886 bytes
 Total-tx-sw-bytes    : 166716 bytes
 Total-rx-bytes       : 166886 byte

 Total-tx-pkt         : 2528 pkts
 Total-rx-pkt         : 2528 pkts
 Total-sw-tx-pkt      : 2526 pkts
 Total-sw-err         : 0 pkts
 Total ARP sent       : 4 pkts
 Total ARP received   : 2 pkts
 maximum-latency   : 35 usec
 average-latency   : 8 usec
 latency-any-error : OK

On csp2s22c03, the show run command displays the graph runtime statistics.