NX-OS Spine/Leaf Operations: vPC, Port-Channels, and Pre-Production Checks
Operate Nexus spine/leaf fabrics without surprises. Covers vPC operational checks, port-channel hygiene, OSPF/BGP underlay verification, and failure drills before go-live.
#networking
42 posts tagged with "networking"
Cisco IOS-XE Edge Baseline: AAA, SSH, ACL, Logging, and IP SLA
Build a production-ready IOS-XE edge router. Covers secure management, IP SLA tracking for real failover, logging configuration, and common mistakes that break production.
Junos Routing Policy That Scales: Policy-Statement Patterns and Safe Defaults
Design maintainable Junos routing policies. Covers policy-statement structure, community naming, prefix-lists, and safe defaults that prevent routing disasters.
FlowSpec: Programmable Filters via BGP
Understand BGP FlowSpec for traffic filtering. Covers FlowSpec rules, BGP distribution, rate limiting, and why FlowSpec enables network-wide filtering from a single point.
VXLAN: Scalable L2 Over L3 Overlay
Configure VXLAN on VyOS for datacenter overlays. Covers VXLAN concepts, static and multicast modes, head-end replication, MTU, and why VXLAN enables scalable Layer 2 networks.
GRE, IPIP, and SIT Tunnels: Simple Point-to-Point Encapsulation
Configure GRE, IPIP, and SIT tunnels on VyOS. Covers tunnel types, MTU considerations, keepalives, GRE keys, and why simple tunnels solve simple problems.
EVPN: Modern Control Plane for L2 and L3 Services
Understand EVPN architecture and concepts. Covers EVPN route types, MAC/IP learning via BGP, multi-homing, VXLAN integration, and why EVPN is the future of overlay networking.
VPLS: Layer 2 VPN Over MPLS
Understand VPLS concepts and configuration. Covers virtual switch model, BGP signaling, pseudowires, MAC learning, and why VPLS provides multipoint L2 connectivity.
L3VPN: MPLS VPN for Multi-Site Connectivity
Configure MPLS L3VPN on VyOS. Covers VPNv4 address family, route distinguishers, route targets, PE-CE routing, and why L3VPN provides scalable multi-tenant connectivity.
BGP-LU: Labeled Unicast for Scalable MPLS Networks
Configure BGP Labeled Unicast on VyOS. Covers label distribution via BGP, inter-AS MPLS, seamless MPLS concepts, and why BGP-LU replaces LDP in modern designs.
MPLS Introduction: Labels, LDP, and Packet Forwarding
Understand MPLS fundamentals on VyOS. Covers label switching, LDP configuration, penultimate hop popping, MPLS forwarding, and why MPLS is still relevant for service provider networks.
BGP Dampening: Suppressing Route Flapping
Configure BGP route dampening on VyOS. Covers dampening parameters, penalty calculation, route suppression, reuse thresholds, and why dampening prevents unstable routes from destabilizing your network.
Route Leaking Between VRFs: Controlled Connectivity
Configure route leaking between VRFs on VyOS. Covers import/export policies, selective leaking, shared services, and why route leaking provides controlled cross-VRF connectivity.
BGP Communities: Signaling Intent Across Networks
Master BGP communities on VyOS. Covers standard, extended, and large communities, common use cases, community-based filtering, and why communities are the language networks speak.
Network Automation with Ansible: From Manual CLI to Infrastructure as Code
A practical guide to automating network infrastructure using Ansible. Real examples from production environments including device configuration, backup strategies, and compliance checking.
Graceful Restart: Maintaining Forwarding During Protocol Restarts
Configure OSPF and BGP graceful restart on VyOS. Covers GR mechanics, helper mode, restart timers, and why graceful restart prevents traffic loss during maintenance.
BFD: Fast Failover Detection for Routing Protocols
Implement BFD on VyOS for sub-second failure detection. Covers BFD timers, integration with BGP and OSPF, multihop BFD, and why routing protocol keepalives are too slow.
Policy Routing Debug: Why Traffic Takes the Wrong Path
Debug policy-based routing on VyOS. Covers rule evaluation order, mark verification, table inspection, common misconfigurations, and why PBR debugging needs systematic verification.
ARP and Neighbor Discovery: Troubleshooting Layer 2 Problems
Debug ARP and IPv6 ND issues on VyOS. Covers ARP table analysis, stale entries, duplicate IP detection, proxy ARP, neighbor discovery, and why Layer 2 problems look like Layer 3 failures.
Packet Capture on VyOS: tcpdump Techniques for Real Debugging
Master packet capture on VyOS for troubleshooting. Covers tcpdump filters, capture strategies, decoding protocols, saving and analyzing captures, and why packets never lie.
Conntrack Deep Dive: Connection Tables, Limits, and Debugging
Master VyOS connection tracking internals. Covers conntrack tables, tuning limits, timeout configuration, debugging full tables, and why conntrack is the invisible stateful firewall engine.
TCP MSS Clamping: When and Why to Adjust Segment Size
Master TCP MSS clamping on VyOS for tunnels and PPPoE. Covers MSS vs MTU, clamping configuration, troubleshooting fragmentation, and why MSS clamping fixes problems MTU changes cannot.
MTR, Tracepath, and PMTUD: Diagnosing Path Problems
Master network path diagnostics on VyOS. Covers MTR interpretation, traceroute variants, PMTUD troubleshooting, detecting packet loss patterns, and why ping alone is never enough.
User Management: Local Users, SSH Keys, and Access Control
Configure VyOS user management properly. Covers local user creation, SSH key authentication, privilege levels, password policies, and why root password should be disabled.
Upgrade Playbook: Safe Upgrades, Rollback, and Migration Testing
Master VyOS upgrades without downtime or disasters. Covers image management, rollback procedures, pre-upgrade testing, migration paths, and why upgrades need a playbook, not improvisation.
Configuration Standards: Naming, Comments, Structure That Scales
Build maintainable VyOS configurations with consistent naming, strategic comments, firewall groups, and policy structure. Learn standards that make configs readable years later.
Configuration Sessions: Parallel Work Without Conflicts
Master VyOS configuration sessions for team environments. Covers session isolation, concurrent editing, merge strategies, and why sessions prevent "who changed what" mysteries.
Commit-Confirm: Your Safety Net Against Self-Lockout
Master VyOS commit-confirm to prevent remote lockouts. Covers automatic rollback, confirmation workflow, timeout tuning, and why every remote change should use confirm.
Automation & GitOps for VyOS: Templates, Backups, Safe Deploy
Practical VyOS automation with Git, templates, and safe deployment practices. Covers config backup strategies, Jinja2 templates, Ansible integration, rollback procedures, and why automation reduces errors only if you have rules of the game.
High Availability: VRRP + State Sync (What You Can and Can't Do)
Honest guide to VyOS high availability using VRRP and conntrack sync. Covers failover configuration, state synchronization, what actually fails over and what doesn't, testing procedures, and why HA is a set of failure scenarios, not a checkbox.
VRF & Segmentation: When VLANs Aren't Enough
Using VRF on VyOS for network isolation that goes beyond VLANs. Covers VRF creation, inter-VRF routing, route leaking, firewalling between VRFs, and maintaining a clear mental model of your segmentation.
BGP on VyOS: Filters Are Not Optional
BGP fundamentals on VyOS using FRR. Covers eBGP/iBGP setup, prefix-lists, route-maps, communities, max-prefix protection, and why BGP without filtering is an incident waiting to happen.
OSPF on VyOS: When Details Break Everything
Practical OSPF configuration on VyOS. Covers areas, passive interfaces, authentication, MTU issues, and the small details that cause OSPF adjacencies to fail silently.
QoS on VyOS: Making Latency Feel Better
Practical traffic shaping and QoS configuration on VyOS. Covers queue disciplines, traffic prioritization, fighting bufferbloat, and understanding where the actual bottleneck is.
Multi-WAN on VyOS: Failover That Actually Works
Configuring reliable multi-WAN failover on VyOS with proper health checking. Covers dual ISP setup, weighted load balancing, SLA monitoring, and why failover without tracking is false confidence.
IPsec on VyOS: Site-to-Site Tunnels That Survive Reality
Configuring reliable IPsec site-to-site VPNs on VyOS. Covers IKEv2 setup, NAT traversal, dead peer detection, rekeying, and systematic debugging when things go wrong.
WireGuard on VyOS: Production Configuration for Site-to-Site and Road Warriors
Complete WireGuard setup on VyOS covering site-to-site tunnels, mobile clients, kill switches, split vs full tunnel, and the two things that make WireGuard stable: MTU and routing policy.
Policy-Based Routing on VyOS: Practical Patterns for Split Routing
How to route specific traffic through different gateways on VyOS. Covers routing by source, destination, domain, and application with real-world examples like split-tunnel VPN.
IPv6 at Home: RA, DHCPv6, and Why Your Firewall Keeps Breaking It
Practical IPv6 configuration on VyOS for home networks. Covers Router Advertisements, DHCPv6, stateless vs stateful addressing, firewall rules, and debugging ND/RA issues.
VyOS Isn't Scary: Building Your First Production-Ready Router
A practical guide to setting up VyOS from scratch. Covers WAN/LAN configuration, NAT, DHCP, DNS forwarding, and basic firewall rules with validation at every step.
IP Management: Getting VM IPs Reliably (DHCP, MAC Mapping, Integrations)
Reliable IP address management for Proxmox VMs. Covers DHCP strategies, MAC-to-IP mapping, router integrations, inventory collection, and why IP addresses are data that must be collected automatically.
Networking Baseline: Bridges, VLANs, Bonding — and the Mistakes I Made
Proxmox networking fundamentals and common pitfalls. Covers Linux bridges, VLAN configuration, bonding modes, network isolation, and why 99% of virtualization network problems are inconsistent Layer 2.