I need to forbid generating some dynamic IP address.

Hi all,

I want to ask you, if it is possible to someway deactivate creating dynamic IP address in address list.
I use a openVPN tunnel and I use for it IP addresses with 30 bit mask.
On client ( ovpn ) Mikrotik create some IP with 30 bit mask ( according to server setting ) - this is OK,
but on ovpn server is the IP without mask ( it means 32 bit mask ).
Data are running via this tunnel, but I use OSPF there. Here is than the problem with OSPF assignment.
LOG: " Discarding Hello packet - mismatch in network mask "
On Mikrotik ( ovpn server ) I have create fixed IP with 30 bit mask, but if the Inet line goes down and up again,
Mikrotik create the some IP address ( dynamic ) but with 32 bit mask. Then I have to delete this dynamic IP and OSPF is running again.
So that simply: I need to forbid generating some dynamic IP.
It is possible?

Thank You very much!
Libor

Go reserve those IPs in the DHCP server by setting them up to be static bound to nonexistent mac addresses.