Have to agree with Roger that this doesn't look like a mosquitto thing - you might well be running that as the single main application, but it looks more like a kernel issue in Raspbian related to the network stack.
Is this over wireless or wired? I have recently tried mosquitto on Raspbian and it worked - but the wireless adapter itself was pretty unreliable and kept losing its SSID association. Strongly suspect Raspbian needs work.
Have to agree with Roger that this doesn't look like a mosquitto thing - you might well be running that as the single main application, but it looks more like a kernel issue in Raspbian related to the network stack.
Is this over wireless or wired? I have recently tried mosquitto on Raspbian and it worked - but the wireless adapter itself was pretty unreliable and kept losing its SSID association. Strongly suspect Raspbian needs work.