Virtual IP to access modem web interface?

RouterOS Beginner Basics
1

I just got a new modem and it has some very specific requirements to interface its web configuration
Must be from 192.168.100.xxx
Must be a static IP

I have a ton of stuff setup on 192.168.88.xxxx with static IPs for a lot of IOT things that would be a PITA to move.

I’ve found some instructions on how to do it on opensense-
https://forum.opnsense.org/index.php?topic=37682.0

However I can’t figure out how to replicate it on routeros

I want a 192.168.88.xxx address (can be static) to appear as a 192.168,100.xxx static address, but it only needs to do it for 192.168.100.1

2

It’s the same principle as described in the OPNsense forum: add an .100.x address on the interface facing the modem and create a src-nat rule:

/ip address
add address=192.168.100.2/30 interface="modem_facing_int"

/ip firewall nat
add action=masquerade chain=srcnat dst-address=192.168.100.1