calculate clocks per packet for:

• single-core
• multi-core with cas
• mutlicore with handoff
• baseline (ip4-routing without nat)

https://gerrit.fd.io/r/#/c/5099/

• patchset #14 - worker handoff
• patchset #16 - atomic CAS

snat config something like this:
set int ip address GigabitEthernet0/8/0 172.16.2.1/24
set int ip address GigabitEthernet0/a/0 172.16.1.1/24
set int state GigabitEthernet0/8/0 up
set int state GigabitEthernet0/a/0 up
snat deterministic add in 10.0.0.0/18 out 1.1.1.0/30
set int snat in GigabitEthernet0/8/0 out GigabitEthernet0/a/0
set ip arp GigabitEthernet0/a/0 172.16.1.2 08:00:27:fc:0c:fd
set ip arp GigabitEthernet0/8/0 172.16.2.2 08:00:27:5d:c7:40
ip route add 10.0.0.0/24 via 172.16.2.2 GigabitEthernet0/8/0