Need help understanding why a particular IP address is assigned to a PPP profile

RouterOS Beginner Basics
1

I’m desperately trying to get a VPN to work on my RB951. I’m reading through this link for how to get OpenVPN to work:

https://wiki.mikrotik.com/wiki/OpenVPN

I got to this step:

Define a profile:

/ppp profile
add change-tcp-mss=default comment=“” local-address=10.15.32.33
name=“your_profile” only-one=default remote-address=ovpn-pool
use-compression=default use-encryption=required use-vj-compression=default

>

I don't understand where 10.15.32.33 comes from. I see the IP pool starts at .34 and the physical interface _ether1_ has .31 assigned to it, but i don't see where .33 comes into play and why. Also, I don't understand why .32 was skipped.

Could someone shed some light on this?
2

You can basically put whatever IP you like as local address, remember this is a point to point network segment; I mean no need to be in the same range.

Whoever set up the router decided to put .33 there, that’s all.

Putting the complete export would maybe reveal why.