BGP EVPN Route Types Explained with Real Output
EVPN route types stop being abstract the moment you read them off a real fabric. Here are Types 2, 3 and 5 from a working Nexus lab.
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.
Latest posts
BGP Route Not in the Routing Table: Why It Is Not Installed
The prefix is in the BGP table and show ip route says % Network not in table. The leading status characters are the whole diagnosis. Captured live on IOS XE 17.18.2 in CML, where a missing next-hop-self leaves an iBGP path valid, inaccessible and never installed.
BGP Neighbor Stuck in Active, Idle or Connect: Decode the State
Active is a failure state and Idle is where the FSM gives up. Organized by the state you are looking at right now, with a lab finding that matters: on IOS XE 17.18.2 both "no route to peer" and "TCP 179 blocked" showed up as Idle.
OMP Deep Dive: Routes, TLOCs, Service Routes, and Path Selection
OMP carries everything in Catalyst SD-WAN: routes, TLOCs, service routes, keys, and policy. This deep dive walks each advertisement type and the path selection logic, with WAN Edge CLI drawn from Cisco's current 20.x documentation.
BGP as the PE-CE Protocol: as-override, allowas-in, and SoO
When two customer sites share an AS number, BGP loop prevention breaks their MPLS L3VPN on purpose. Reproduce the failure in a CML lab and fix it three ways: as-override, allowas-in, and SoO, with real output for each.
MPLS VPNv6 and 6VPE: IPv6 L3VPN over an IPv4 Core
6VPE carries IPv6 L3VPN across an IPv4 MPLS core using the same VRFs, RTs, and MP-BGP sessions you already run. This article builds it in CML and shows the two-label stack that makes it work.
Multi-Protocol Redistribution: The CCIE Scenarios That Break Networks
Two-point redistribution is where networks go to die. This article builds the classic CCIE failure for real in a CML lab, shows a route being re-injected into the protocol it came from, and then fixes it with the exact output at each step.
Expert BGP Troubleshooting: Five Broken Scenarios, Ticket Style
Five broken BGP scenarios built and broken for real in a CML lab, each worked ticket style with the actual diagnostic output and the actual fix. The method: every BGP problem is one of four things, checked in order.
IPv6 over BGP: MP-BGP for IPv6 and 6PE Explained
6PE carries IPv6 prefixes across an untouched IPv4 MPLS core using MP-BGP and labels. This post builds a working deployment on Cisco IOS XE and shows the labels, the IPv4-mapped next hops, and an end-to-end IPv6 traceroute.
BGP Multipath and Load Sharing: eBGP, iBGP, and eiBGP
BGP multipath is one config line, but the rules for when a second path is accepted are not. Cover eBGP, iBGP, and eiBGP multipath on Cisco IOS XE with lab output, including the next-hop rewrite that can hide a real misconfiguration.
Designing BGP Policy with Communities: A Practical Framework
A well-designed BGP community scheme turns per-neighbor route-maps into a scalable signaling system. This guide builds one end to end on IOS XE, proves it with lab output, and includes a working RTBH trigger.
BGP Route Dampening: Penalties, Half-Lives, and Why It Fell Out of Favor
Dampening penalises a prefix for flapping and refuses to use it even after it recovers. Captured live on CML with IOS XE 17.18.2: penalty 2818 from three flaps, the prefix held at *d while an identical prefix from the same neighbor stays best, plus the advertisement-interval gotcha that makes...