# networking

An introduction to Envoy Proxy's architecture — listeners, clusters, filters, and the xDS dynamic configuration API. Covers static configuration for standalone use and how Envoy fits into service meshes like Istio.

Advanced Envoy traffic management — configuring retries with exponential backoff, per-request timeouts, weighted canary routing, global rate limiting, and fault injection for resilience testing.

Advanced HAProxy SSL configuration — multi-domain SNI routing from a single frontend, mutual TLS (mTLS) for service-to-service authentication, certificate management, and OCSP stapling.

A comprehensive HAProxy configuration guide covering frontends, backends, balance algorithms, active health checks, SSL termination, ACLs, rate limiting, and the runtime socket API.

Step-by-step guide to building a highly available load balancer pair with HAProxy and Keepalived — covering the full stack from VIP configuration to health checks, stats, and SSL termination.

How to configure Keepalived for automatic failover using VRRP — setting up master/backup pairs, virtual IPs, health-check scripts, and combining it with HAProxy or Nginx for zero-downtime load balancer HA.

Resolve DNS lookup failures inside Docker containers — fix resolv.conf, custom networks, and upstream DNS configuration issues.

A practical DNS troubleshooting guide for DevOps engineers — dig commands, nslookup patterns, common production failure modes, and how to diagnose each one.

The sysctl knobs that actually improve Linux network throughput, latency, and connection handling — with benchmarks and safe production values.

How to design multi-cloud connectivity between AWS and Azure using Transit Gateway and Virtual WAN — patterns, pitfalls, and cost tradeoffs.

A data-driven playbook for cutting AWS costs across compute, storage, networking, and reserved capacity with real numbers and actions.

Linux networking commands cheat sheet for troubleshooting — interfaces, routing, DNS lookups, connections, iptables firewalls, and tcpdump packet capture.

Understand Azure's essential services — VMs, Storage, VNets, Azure AD (Entra ID), AKS, App Service, and Azure DevOps for infrastructure automation.

Configure HAProxy for HTTP and TCP load balancing — installation, frontends, backends, health checks, ACLs, SSL termination, and the stats dashboard.

Implement automatic failover for HAProxy and Nginx using Keepalived with VRRP — virtual IPs, health checks, and split-brain prevention.

Configure Linux network interfaces, set up iptables/nftables/firewalld rules, troubleshoot connectivity with ss, ip, dig, and tcpdump, and secure your servers.

A practical comparison of Kubernetes Ingress and Gateway API, with a migration strategy that won't take down your production traffic.

How to implement zero-trust networking in Kubernetes using NetworkPolicies — deny by default, allow by exception, and sleep better at night.