When the network fluctuates, such as DSL disconnection(pppoe), or udpspeeder completes startup earlier than the dhcp, there is a certain probability that no traffic will be transmitted. After restarting, it will be ok.
Is it because of libev? I have updated to the latest version of libev and recompiled udpspeeder, but there is no change. I am currently restarting udpspeeder in if-up.d.