Trouble with PPPOE and 1:1 NAT

RouterOS Beginner Basics
1

Hi, Would love some advise on setting up a Routerboard 750. I have a block of static IP addresses form our ISP xxx.xxx.xxx.121/29. I have an ADSL modem in 1483 bridged mode providing ADSL connection and plugged into the port 5 Routerboard which has 5 ports. (It started on port 1 but moved it to port 5 as i read on the forum that some people had problems with PPPOE on port 1)
I want to 1:1 NAT four of the static addresses to each of the other 4 ports.
I have assigned IP address to each interface

IF 1 192.168.101.1/24
IF 2 192.168.102.1/24
IF 3 192.168.103.1/24
IF 4 192.168.104.1/24
IF 5 xxx.xxx.xxx.121/29
PPPOE on port 5
The PPPOE connects and logs on to the ISP according to the status
So I tried to 1:1 NAT
xxx.xxx.xxx.122 → 192.168.101.1
xxx.xxx.xxx.123 → 192.168.102.1
xxx.xxx.xxx.124 → 192.168.103.1
xxx.xxx.xxx.125 → 192.168.104.1
using IP → Firewall →
dstnat xxx.xxx.xxx.122 netmap 192.168.101.1
srcnat 192.168.101.1 netmap xxx.xxx.xxx.121 (ISP gateway)
dstnat xxx.xxx.xxx.123 netmap 192.168.102.1
srcnat 192.168.101.1 netmap xxx.xxx.xxx.121 (ISP gateway)
dstnat xxx.xxx.xxx.124 netmap 192.168.103.1
srcnat 192.168.101.1 netmap xxx.xxx.xxx.121 (ISP gateway)
dstnat xxx.xxx.xxx.125 netmap 192.168.104.1
srcnat 192.168.101.1 netmap xxx.xxx.xxx.121 (ISP gateway)

I tried to set the interface setting on these to the PPPOE but that generates an error.
Currently there is no connection between the 192.168.10x networks and the ISP

Could someone tell me how to set up th connection through the PPPOE
Thank you

2

I am a little confused on a couple of counts:

  1. You seem to be assigning your public IPs to Ether 5 but from the description aren’t these being provided to you over PPPoE? If they are then the addresses should end up assigned to the PPPoE interface not Ether 5.

  2. The NAT entries look like the public IPs are being NATed to the routers IPs on those other interfaces. Normally you would NAT to a host on one of those networks. Perhaps you can explain what you are trying to achieve because NATing back to the router’s own interfaces seems unhelpful.