https://forum.opnsense.org/index.php?topic=34026.msg164617#msg164617 I had this issue for a long time but it was finally resolved with the netmap changes and it's not been a problem. After the latest release this has happened three times now. I'm not sure if it's due to the new intel drivers or what. But the symptoms are exactly the same as before. I'm going to test the emulated netmap drivers again as that resolved it last time for me. But I think there was a regression somewhere.