SRC-NAT With IP Pool without configure IP on WAN Interface

RouterOS General
1

Hello!
I have a task that I’ve done many times in other vendors. Tried on Mikrotik but not working (maybe something is missing in my configs)

I have a Public Pool 45.XX.YY.ZZ/24
45.XX.YY.1/24 is configured ISP Router as my gateway
45.XX.YY.2/24 is configured in my router

I want to configure all my users (about 1200 PPPoE Users) with private IP address 173.16.0.0/16 to go to internet with other IP of my range 45.XX.YY.11-45.XX.YY.200
I have tried to set on firewall

add chain=srcnat src-address=173.16.0.0/16 action=src-nat to-addresses=45.XX.YY.11-45.XX.YY.200

But this work only if I configure all those IP from 11 to 200 to WAN Interface.
Is there any way to make this work without adding all IP to WAN Interface

Note** - Tried this already on CISCO and FORTINET and work without configuring all IP, but just with creating an IP Pool.

Regards.

2

You have to switch arp=proxy-arp on the WAN interface, otherwise the upstream ISP’s router gets no ARP responses for these “virtual” addresses.

3

Already tried this, but does not work!
I’ve done this when I set a Public IP to a PPPoE user, but i my case I want to just NAT and MASK my IP with a different one from my Router IP!

4

I understand that the source addresses you NAT the clients to are different from the router’s own one, but they are still from the same subnet as the router’s own one. So OK, try arp=local-proxy-arp instead, although I was pretty sure that connection tracking did interwork with proxy-arp.

5

The arp=proxy-arp works only when router has route to requested IP address pointing elsewhere (e.g. when it’s assigned to PPPoE client), but as I understand it, it’s not the case here. With arp=local-proxy-arp it will answer also for other addresses on same local subnet.