Proxy-ARP feature
Description

A router with properly configured proxy ARP feature acts like a transparent ARP proxy between directly connected networks. Consider the following network diagram:

Proxy ARP Diagram

Suppose the host A needs to communicate to host C. To do this, it needs to know host's C MAC address. As shown on the diagram above, host A has /24 network mask. That makes host A to believe that it is directly connected to the whole 192.168.0.0/24 network. When a computer needs to communicate to another one on a directly connected network, it sends a broadcast ARP request. Therefore host A sends a broadcast ARP request for the host C MAC address.

Broadcast ARP requests are sent to the broadcast MAC address FF:FF:FF:FF:FF:FF. Since the ARP request is a broadcast, it will reach all hosts in the network A, including the router R1, but it will not reach host C, because routers do not forward broadcasts by default. A router with enabled proxy ARP knows that the host C is on another subnet and will reply with its own MAC adress. The router with enabled proxy ARP always answer with its own MAC address if it has a route to the destination.

current version is 3.25 and proxy-arp is working as far as we know.

please upgrade to that version and contact support right away with supout.rif file included when proxy arp is not working.

/ip route print
/ip address print

what interface requests come from?

where's http://forum.mikrotik.com/viewtopic.php ... 82#p160482 ?

/ip route print
/ip address print

post here the result

[admin@MikroTik] > ip route print 
Flags: X - disabled, A - active, D - dynamic, 
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, 
B - blackhole, U - unreachable, P - prohibit 
 #      DST-ADDRESS        PREF-SRC        G GATEWAY                   DISTANCE INTERFACE 
 0 ADC  192.168.0.0/25     192.168.0.1                                 0        ether1    
 1 ADC  192.168.0.128/25   192.168.0.129                               0        ether2

[admin@MikroTik] > /ip address print 
Flags: X - disabled, I - invalid, D - dynamic 
 #   ADDRESS            NETWORK         BROADCAST       INTERFACE              
 0   192.168.0.1/25     192.168.0.0     192.168.0.127   ether1                 
 1   192.168.0.129/25   192.168.0.128   192.168.0.255   ether2 

hm... should work. and worked for me earlier - now I just don't use it...