Using a RB750 router firmware=5.8 and 5.14 with a Bridge setup on ether4-LAN and ether5-lowspeed.
I have a LAN that has a low speed radio link to a few devices.
I setup a Bridge, and add filters to accept each ARP request to the devices and drop all other ARP requests.
This greatly reduces unwanted traffic over the low speed (16kbps) radio.
The downside is I have to create a rule for every device at that site, because in the ARP dst-address (initial arp request) you can only put in a single matching IP address like 172.16.72.11.
why can’t I use the “ARP List” and a single drop filter?
I could not get the ARP Reply-Only feature to work.. tried on bridge, on interfaces, and every possible combination.
Yes, I did setup the IP/MAC entries in the “ARP List”.
Routing is not a option because all devices on LAN and over radio link are in the same IP subnet.
If your trying to eliminate some traffic on a bridge then maybe you could drop broadcast traffic forwarding through that bridge.
/interface bridge filter
add action=drop chain=forward dst-mac-address=FF:FF:FF:FF:FF:FF/FF:FF:FF:FF:FF:FF
Yes, I actually have 3 more filters after the ARP filters: drop broadcast, drop, multicast, drop mikrotik mac-telnet
If I don’t process the ARP traffic first, then no connections can be made when the “drop broadcast” filter hits.
I was trying to make a better more efficient way of filtering, instead of having to add an “allow” filter for each single IP address ARPrequest, but to have a single filter that uses a list, or have the ARP reply-only feature actually work, then I can add the entries to the ARP list.
Also, all my filters additionally use “interface, out, ether5” so it will not drop any traffic originating from low speed to LAN.
Thanks.