Cause Analysis of UDP packet loss in linux kernel 1. UDP checksum and error phenomenon: You can use netstat-su to view UDP error packets. Tcpdump packet capture: Enable the captured udp packet in wireshark and enable the checksum option. Solution: Search for Link faults www.2cto.com 2. Firewall enabling phenomenon: packets on specific ports cannot be received. Solution: Disable using service iptables stop. 3. rp_filter enabled: tcpdump has packets and the protocol stack cannot receive them. A package sent from one address cannot receive any package, but the package sent from another address is okay. Solution: Set rp_filter in/etc/sysctl. conf to 0. See: 2.6.32 is enabled by default. 4. Application performance problems. The buffer is full. Symptom: The application can receive UDP packets intermittently. Solution: Use the vmstat and top commands to detect cpu or IO overload. Increase the buffer and optimize the program.