pptp source address

Hi,

pptp vpn between two mikrotik. server mirkotik has 172.16.10.1 for pptp interface and pptp client mirkotik has 172.16.10.2. On server side there is a netwrok 192.168.100/24 and on the clinet side is 192.168.200.0/24. Static routes are added to route traffic for remote network through pptp tunnel. What i noticed is that when I am pinging from one side to another on torch source ip instead of computer is ip addresses of the tunnel. So if i pinging from 192.168.200.15 to 192.168.100.10 on server side i see src address in torch on server side 172.16.10.2 (but the source is 192.168.100.10). The problem is that 192.168.100.10 has default gateway through another interface and static route for 192.168.100.0/24 through LAN interface. Now i must also put the static route for 172.16.10.0/30 so that it knows return traffic back. Why the source is not my computer instead of the pptp interace address?

Thanks

Do you may have a masquerade or src-nat rule to allow Internet traffic out the default gateway that does not have an outgoing interface specified? This could cause the LAN address to be masqueraded outbound on the photo tunnel?