I just had a case of a broadcasting problem because a router using 2.9.51 didn’t stop transmitting when the destination host on the lan disappeared.
A host was receiving a UDP stream, the host disappeared, but the traffic kept coming in. The traffic ended up broadcasting instead of unicasting for some reason. After about 12 hours, I verified the destination host wasn’t reachable, deleted the arp entry for that mac address/ip and the traffic and broadcasting stopped. I’m guessing at that point, the sending host must have received some unreachable message and stopped. The arp entry did not come back, so I will assume the MT router just kept that arp entry for too long.
Questions…
Is there any arp timeout feature in the various newer versions of routerOS?
What does it take to make something disappear from the arp table in routerOS, besides manually removing?