How to divert to NAT only packets leaving from specific interface ?

Hello folks.

Assume we have router with 3 active interfaces

  1. 192.168.1.3/24
  2. 192.168.2.3/24
  3. 192.168.3.3/24

we also have default gateway installed to 192.168.1.1 and several static-routes ex.
dst-address=10.255.245.0/24 gateway=192.168.2.4
dst-address=10.255.246.0/24 gateway=192.168.3.4

How can I divert to NAT only packets leaving router via default-gw (interface1) leaving other packets unchanged ?

RGDS

Solved