I'm running tor relay on FreeBSD 11.1, and not long ago the system started to occasionally stop responding to the network with kernel: [zone: mbuf_cluster] kern.ipc.nmbclusters limit reached accompanied with kernel: sonewconn: pcb 0xfffff80003c61570: Listen queue overflow: 193 already in queue awaiting acceptance (211 occurrences) messages in the logs. It first happened on Dec 13 and repeated 3 times, the approximate lifetime of the relay is ~1 day. Seems like a DOS attack which makes tor open a lot of connections and eat all the mbuf space. I don't see any peaks on trafic or pps graphs though, and there are no messages in tor log. I'm currently trying to gather more information. **Trac**: **Username**: AMDmi3