Network tools
Commands
- Show SYN_REC packets
ss -pitl -o state syn-recv -e
netstat -anplt | grep SYN_REC
HowTO
Advanced packet tshoot
Trace TCP Connections
- Capture packets
tcpdump -nnn -w /tmp/tcpdump.out -s 1580
- Show the simple trace
tcptrace netdump-20171110022044.out
- Show the trace by connection ID 3079
tcptrace -o3079 netdump-20171110022044.out
- Debug problematic packet with detailed and long output
tcptrace -l -o3079 netdump-20171110022044.out
And so on.. :P
Articles
- http://prefetch.net/blog/index.php/2006/04/17/debugging-tcp-connections-with-tcptrace/
- http://veithen.github.io/2014/01/01/how-tcp-backlog-works-in-linux.html
- https://tweaked.io/guide/kernel/