Linux networking is one kernel interface with four generations of tools stacked in front of it, and the commands you need at 2am are never the ones you used last week. The PingLabz Linux Networking Field Reference puts the whole toolkit on ten printable pages: iproute2, sockets, DNS, capture, monitors and all three firewall front ends, with real output from a live lab beside every command.
It is the printable companion to the complete guide to Linux networking commands and the 2026 field reference article. Nothing in it is invented. Every capture came off a Debian 13 host bridged into a CML topology, four router hops from the far end.
What is inside
- Page 1 - Quick Reference. The five commands that solve most incidents, the
ipobject model, global flags, one install line for every tool in the document, and seven golden rules. - Page 2 - Addressing and Interfaces. ip addr and ip link, ethtool, nmcli, how to read UP against LOWER_UP, and which config layer actually survives a reboot.
- Page 3 - Routing and Neighbors. ip route, ip route get, policy routing with ip rule in three commands, route field meanings, and the neighbor state machine.
- Page 4 - Path Testing and MTU. ping, traceroute in all three modes, mtr, tracepath, how to read loss at one hop, and the MTU test that explains most VPN complaints.
- Page 5 - Sockets, Services and DNS. ss filters and TCP states, lsof, dig against host against nslookup, and the four-layer name resolution order.
- Page 6 - Ports, Transfer and Tunnels. nc, curl timing breakdowns, wget, socat, all four SSH forwarding modes, and what refused, filtered and reset each tell you.
- Page 7 - Capture and Monitoring. tcpdump and tshark filters, ngrep, the bandwidth monitors compared, the missing-frame diagnosis table, and why offloads make captures lie.
- Page 8 - Firewalls. iptables, nftables and ufw side by side, chain evaluation order, and the five traps that lock people out of their own hosts.
- Page 9 - Troubleshooting Decision Tree. Ten symptoms, the likely cause of each, and the exact command that proves it. Plus the seven-step order and seven one-liners worth stealing.
- Page 10 - Reading Real Output, Annotated. Interface counters explained field by field, the router side of the same link, and copy-paste blocks for bringing a host onto a segment and proving a port end to end.
Dense, print-friendly and built to be taped to a monitor. If you support Linux hosts and network gear in the same job, page 9 alone will pay for the download.
Get the PDF
The download is free. You just need a PingLabz account, which is also free and takes about ten seconds. No card, no spam, just an email so we can tell you when the next cluster reference lands.