Defining traffic in Ostinato 

no need to define devices. Just add streams and in "Protocol Data", open "Media Access Protocol" and make destination the next hop mac (ip neigh show) and source as increment to simulate MAC addresses

Now add the IPv4 IPs

and make sure that the number of packets sent is the same as your source amount

 

NAT

symmetric NAT = Dynamic PAT (Cisco FWs)

 ASA Firewall allow traceroute

access-list outside_acl_in extended permit icmp any any time-exceeded
access-list outside_acl_in extended permit icmp any any unreachable
!
access-group outside_acl_in in interface outside

!

policy-map global_policy

 class inspection_default

  inspect icmp

  inspect icmp error