Install Zabbix 7.0 LTS in Docker Alongside Grafana
Two monitoring platforms, one Ubuntu box, zero port collisions. Plus the built-in host that cannot reach its own agent, and why apt was not an option.
Go Deeper on Enterprise Networking
In-depth tutorials on OSPF, BGP, 802.1X, and more- for engineers who want to understand the why, not just the how.
OSPF
Open Shortest Path First, the link-state IGP behind most enterprise networks. Articles tagged OSPF cover neighbor relationships, LSA types, areas, DR/BDR election, and Cisco IOS XE configuration.
61 posts
BGP
Border Gateway Protocol, the path-vector protocol that holds the internet together and increasingly runs inside enterprise data centers. Articles tagged BGP cover fundamentals, neighbor states, path attributes, best-path selection, traffic engineering, and Cisco IOS XE configuration.
60 posts
802.1X
Port-based network access control, the standard for authenticating users and devices onto wired and wireless networks. Articles tagged 802.1X cover supplicant and authenticator behavior, RADIUS, EAP methods, Cisco ISE, dynamic VLANs, dACLs, host modes, and phased deployment.
38 posts
VLAN
Virtual LANs and Layer 2 switching, the foundation of every campus network. Articles tagged VLAN cover fundamentals, trunking, inter-VLAN routing, EtherChannel, troubleshooting, and campus design on Cisco Catalyst switches.
47 posts
Wireless
Enterprise Wi-Fi on Cisco Catalyst 9800, the WLC platform that replaced the AireOS generation. Articles tagged Wireless cover the configuration model, AP join, WPA3, FlexConnect, RRM, fast roaming, SSO HA, and IOS XE troubleshooting.
52 posts
STP
Spanning Tree Protocol, the loop-prevention mechanism that keeps Layer 2 networks stable. Articles tagged STP cover port roles and states, RSTP and MST, root bridge configuration, BPDU Guard and Root Guard hardening, and Cisco Catalyst troubleshooting.
36 posts
Latest posts
How to Install Grafana Enterprise on Ubuntu Server
From an empty Ubuntu box to a Grafana login screen: APT repo, systemd, and the 20-second gotcha that makes people think the install failed.
members
Linux Networking Field Reference (10-Page Printable Cheat-Sheet)
Ten printable pages of Linux networking commands, flags and real lab output, including a ten-symptom troubleshooting decision tree. Free for members.
Top Linux Networking Commands: The 2026 Field Reference
Every Linux networking command that matters, grouped by the question it answers, with real captures from a four-hop lab and the triage order to run them in.
ufw: Simple Firewalling on Debian and Ubuntu
Enable ufw without losing your SSH session, learn the rule grammar, and see exactly which iptables chains it builds underneath.
nftables: The Modern Linux Firewall
Your iptables rules already run on nftables. Handles, named sets, inet tables and atomic ruleset loads, all proven with real output from a live lab.
iptables Fundamentals: Tables, Chains, Real Rules
Tables, chains and rule order, demonstrated with real captures from a Debian host in a live lab: DROP against REJECT timing, conntrack, logging and NAT.
/proc/net and Networking sysctls: Where the Numbers Come From
Every Linux networking tool is a formatter over a handful of kernel files. Here is what is in them, how to read the hex, and what happens when you change the sysctls that matter.
iftop, nload, bmon, vnstat, nethogs Compared
Five live bandwidth monitors pointed at the same flow at the same time, with real terminal frames and a reconciliation of why they all report different numbers.
ngrep: grep for Network Traffic
Pattern matching against live packet payloads. The syntax, the hex mode, the file interop, and a real capture showing the server name leaking out of an encrypted session.
tshark: Wireshark in the Terminal
Wireshark’s full dissector library driven from an SSH session: capture filters against display filters, custom field output, ring buffers and the statistics taps that make triage fast.
SSH Beyond Login: Tunnels, Jump Hosts, scp/sftp
Local, remote and dynamic forwards, ProxyJump instead of agent forwarding, scp -O against IOS XE, and why telnet is still a fine port tester.