Inspect active sockets and network connections with the fast, kernel-aware `ss` utility. 06.05.2026 | reading time: 2 min Meet `ss`: the iproute2 utility to inspect sockets and active network connections quickly and precisely; use it to audit listening ports, observe established sessions and tie sockets to processes. Quick Audit Run `ss -tuln` to list listening TCP and UDP sockets; typical output looks like: `State Recv-Q Send-Q Local Address:Port Peer Address:Port` `LISTEN 0 128 0.0.0.0:22 0.0.0.0:*` `LISTEN 0 128 127.0.0.1:5432 0.0.0.0:*`. Filter and Inspect Drill down with `ss -tunap` to show TCP and UDP sockets with PID/program information; use `ss -s` for a compact summary and `ss state established` to list established connections for live troubleshooting. When to Reach for Others For packet-level capture use `tcpdump` or Wireshark, consult `lsof -i` to map sockets to file descriptors, and fall back to `netstat` on older systems that lack iproute2 utilities. Next Steps Practice on a live host: check services with `ss -p`, cross-check PIDs with `ps` and close or investigate unexpected listeners; keep improving LINUX skills and consider certifications such as CompTIA Linux+ or LPIC-1, with bitsandbytes.academy offering intensive exam preparation. Join Bits & Bytes Academy First class LINUX exam preparation. utilities network troubleshooting
