set interfaces ethernet eth0 address '192.168.122.5/24'
set interfaces ethernet eth1 address '192.168.99.1/24'

set vpp nat44 address-pool translation interface 'eth1'
set vpp nat44 interface inside 'eth0'
set vpp nat44 interface outside 'eth1'

set vpp settings interface eth1 driver 'dpdk'
set vpp settings interface eth0 driver 'dpdk'

vyos@vyos# commit
[ vpp ]
Traceback (most recent call last):
  File "/usr/libexec/vyos/services/vyos-configd", line 156, in run_script
    script.apply(c)
  File "/usr/libexec/vyos/conf_mode/vpp.py", line 784, in apply
    call_dependents()
  File "/usr/lib/python3/dist-packages/vyos/configdep.py", line 172, in call_dependents
    f()
  File "/usr/lib/python3/dist-packages/vyos/configdep.py", line 141, in func_impl
    run_conditionally(target, tag_value, config)
  File "/usr/lib/python3/dist-packages/vyos/configdep.py", line 132, in run_conditionally
    run_config_mode_script(target, config)
  File "/usr/lib/python3/dist-packages/vyos/configdep.py", line 108, in run_config_mode_script
    mod.verify(c)
  File "/usr/libexec/vyos/conf_mode/vpp_nat.py", line 202, in verify
    get_interface_address(interface)
IndexError: list index out of range

[[vpp]] failed
Commit failed

[edit]