You see the "incorrect" checksums due to a feature called TCP checksum offloading. The checksum fields for outgoing TCP packets are not pre-calculated by the operating system but set to 0 and left for calculation by the NIC processor. The Wireshark FAQ has a more detailed explanation.

You should only see incorrect checksums on packets sent by your machine. This is not specific to Wireshark, any packet capture software working at this level will produce similar results.

If you see checksum fails on received packets, there might be a problem indeed - these packets are discarded by the TCP stack and trigger a retransmission as well as congestion control algorithms - which will have a direct impact on data throughput.


使用 tcpdump --dont-verify-checksums 或者 tcpdump -K 忽略 checksum 检查。