ss: The Modern Socket Statistics Tool
Queue columns that tell you which end stopped working, filters that run in the kernel, and the TCP internals nothing else on the box will give you.
Jaime
Latest posts — page 3
tracepath and Path MTU Discovery on Linux
Small things work and big things hang. One unprivileged command finds the narrow link, and one iptables rule shows what a black hole looks like.
mtr: Continuous Path Monitoring on Linux
Loss and latency per hop against a link with 12 percent loss injected on purpose, and the one rule that separates real loss from cosmetic loss.
traceroute: UDP, ICMP, and TCP Modes Explained
Three probe types down one four hop path, the packets on the wire for each, and the ICMP rate limit that makes a perfect path look broken.
nmcli and nmtui: Managing Connections from the CLI
Devices against connection profiles, the activation step everybody forgets, and how to make a configuration survive a reboot.
ethtool: Link Speed, Duplex, Offloads, NIC Stats
The driver layer below the kernel: link settings, offloads that make packet captures disagree with the wire, rings, and where host-side drops show up.
ifconfig, route, netstat: Legacy net-tools to iproute2
The full command map, and the same host through both toolsets so you can see exactly what the legacy tools hide from you.
ARP on Linux: ip neigh, arp, and Neighbor States
The six-state neighbor machine walked live on a real lab, the tunables behind it, and why arp -n cannot show you any of it.
ip route: Managing the Linux Routing Table
Every field in a route line, get against show, blackhole routes, the replace gotcha, and policy routing with multiple tables.
The Linux ip Command: The Complete Guide
The grammar, the four objects you use every day, the output modifiers that make it readable, and how to create interfaces out of nothing.
VXLAN EVPN Troubleshooting: What Actually Breaks
Four faults hit in a real Nexus fabric, the output that identified them, and an ordered method for the next one.
EVPN L3VNI and the Distributed Anycast Gateway
Symmetric IRB routes between VNIs on the leaf that receives the packet. Here is the L3VNI build and the real output that proves it worked.