Apple

--- changed en1 to en0

$ sudo sysctl -w net.inet.ip.forwarding=1

$ sudo natd -interface en0

--- changed "any to any" by the IP addresses? Is that correct?

$ sudo ipfw add divert natd ip from 10.100.4.100 to 10.110.4.100 via en0

Anyway commands seems to be accepted but it doesn't work.

Am I missing something?

The default interface may not be en0 or en1. To get the default interface:

set my_interface to do shell script "netstat -rn -f inet | egrep \"^default\" | awk '{print $6}’ "

However, not really sure what you are trying to do. If you want the client machine to accessible at a different IP address, you can set it up with virtual IP’s:

https://gerrydevstory.com/2012/08/20/how-to-create-virtual-network-interface-on-mac-os-x/

Jim Weisbin | C.T.O. | human