Rick Cao | Network EngineerPersonal resume and technical blog covering networking, automation and other things I interest in.https://noerror.cc/Finding an SMTP STARTTLS Failure with TCP Sequence Analysishttps://noerror.cc/blog/packet-capture-analysis-case/https://noerror.cc/blog/packet-capture-analysis-case/How dual-segment packet captures, SACK blocks, and cross-path comparison exposed a TLS handshake gap caused by likely MTU/PMTUD issues.Tue, 11 Aug 2026 00:00:00 GMT