VPN servers and firewall configuration

RouterOS General
1

how to setup firewall rules to limit clients following this guide:
http://technet.microsoft.com/en-us/library/cc737500.aspx

  • Destination IP address of the VPN server’s Internet interface, subnet mask of 255.255.255.255, and IP Protocol ID of 47.
    This filter allows PPTP tunneled data from the PPTP client to the PPTP server.
2

id 47 is GRE protocol

3

thanks.
http://forum.mikrotik.com/t/how-to-allow-pptp-at-firewall/9580/1

chain=input protocol=47 action=accept