Implementation of Proxy-ARP Network
There are several modes of ARP in MikroTik interface between Enabled ( default ), Reply-Only, Disabled, Proxy-ARP. Each mode has a function that we can adjust to the needs of the existing network.
Mode Reply-Only 've discussed in previous articles which are commonly used for network security functions. This article will discuss how the function of fashion 'Proxy-ARP' if it is implemented in the network.
The use mode 'Proxy-ARP' is usually used when we have a network where the dial-in client (PPP, PPPoE, PPTP, etc.) using the IP address with the same range of the local network (LAN). Basically when there is a configuration of IP addresses with the same subnet on more than one interface of the router, then this will make the routing table is not going well. The effect between dial-in client and the client on the local network cannot be communication.
In this condition, Proxy-ARP mode can be used. To be able to communicate with one another, ARP mode on the interface needs to be changed, the default is ' Enabled ' to ' Proxy-ARP '.
ARP-Proxy Configuration
We just need to modify the client ethernet interface where the local network is connected.
Furthermore, for dial-in client (PPTP) regular connection to the router. After connecting the client will automatically obtain IP address allocation of PPTP connections. For example, PPTP Server configuration itself can be seen in the article here.
Then we can test PING from LAN to VPN Client or vice versa. With the configuration of 'Proxy-ARP' we've done above, between the client was able to communicate.
If we check the ARP-List in one client on the LAN, it will display the IP address of the VPN Client with MAC-addresses that are all referring to the MAC address of the router LAN ethernet interface.
*) Note:
With the above topology, make sure to allocate the IP address actually allocated specifically. 192.168.88.2-192.168.88.50 eg IP address range for the LAN client and the rest of the VPN Client. If there is the same IP address on both the course of communication between these devices still can not be done (sort happened IP Conflict).
Soruce / more info : Mikrotik Indonesia.
