hi , i have a server from ovh , and it uses arp based network .
and for a mikrotik vps i have faced problems configuring the network.
here is an example of the network details :
server main ip : 111.x.x.x
server gateway : 111.x.x.254
server mac : aa:bb:cc:dd:ee:ff
vps ( virtual machines ip ) : 222.x.x.x ( is not in the same range as server ip range )
server subnet : 255.255.255.255
vps gateway : 111.x.x.254
, the server virtualization is vmware ESXi 4.1 . so i set the mac address on the ethernet before turning on the vm.
in the linux or in windows 2003 or 2008 there is no problem with ovh servers but in mikrotik , the ping of the vm ip wont returning anything .
till mikrotik version 5.0rc7 there is subnet interface , i configure the router this way :
from console :
/ip adress
add address 222.x.x.x/25 subnet=255.255.255.255 broadcast=111.x.x.254
interface : ether1
then from the same vm ( windows ) on that server and ip range , i open a winbox and connect to the mikrotik vm via mac,
then from menu : ip → arp , i add ip and the mac for the vm
then from menu : ip → route , i add gateway :
dst address 0.0.0.0/0 gateway 111.x.x.254
then the ip ping from that windows will return reply from ip 222.x.x.x
then the gateway will become reachable via ether1
then i set dns , and the ip will work fine
( i can ping that vm ip from any internet network , or i can ping google.com via terminal in mikrotik. )
now here is the problem with mikrotik 5.14 or as i tested from 5.0rc8 ,
there is no subnet ( broadcast ) interface in /ip address , and i cant set broadcast = 255.255.255.255 and also i cant set gateway on another ip range ! ( i cannot add gateway as 111.x.x.x. it simply changes the gateway to 222.x.x.128 for example.)
and i should downgrade the mikrotik too max verssion of 5.0rc7
now what should i do if i want to use newer versions of mikrotik in ovh datacenter ? 
even when i configure a mikrotik vm 5.0rc7 then upgrade it to 5.0rc8 , the ip configuration will loose the gateway
and gateway 111.x.x.254 will not be reachable on ether1 with ip 111.x.x.x
any guides will be appreciated .
www.mikrotik.com/download/CHANGELOG_5
What’s new in 5.0rc8 (2011-Feb-01 14:03):
*) added led trigger - change leds on different events;
*) snmp - restored access to routing tables;
*) snmp - fixed memory leak for OID 1.3.6.1.2.1.25.2;
*) ipsec - added ipv6 support;
*) removed broadcast setting from ip address;