I have just had a 1GB Fibre line installed - with a /27 subnet.
I have a mikrotik router that I want to setup to share those IP addresses out to WISP clients via PPPoE and a static IP address - which I have been able to achieve.
I want to place a second mikrotik router behind the first one, allocating a /29 block of addresses to this router for out own internal servers. Again, I have gotten this to work - but I am struggling to get the correct IP address assigned to the server when it sends traffic out. For example - incoming mail to the exchange server at xxx.xxx.xxx.28 reaches the server - but when mail is sent from the server out of the network it is seen as the first address - i.e. xxx.xxx.xxx.24. I have tried src-nat and dst-nat but it doesn't seem to make any difference.