MPLS L3VPN with MP-BGP and VPNv4
MPLS L3VPN architecture: VRFs, Route Distinguishers, Route Targets, MP-BGP for VPNv4, the two-label stack, PE-CE routing, and the Cisco IOS XE configuration.
7 min read
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.
40 posts
MP-BGP: Multiprotocol BGP Address Families Explained
MP-BGP (RFC 4760) is what lets a single BGP session carry IPv6, VPNv4, EVPN, and more. The AFI/SAFI model, route distinguishers, and how modern data center fabrics use MP-BGP for everything.
6 min read
BGP Neighbor States: The 6-State FSM and How to Diagnose It
BGP's finite state machine has six states: Idle, Connect, Active, OpenSent, OpenConfirm, Established. What each means, why Active is a problem state, and the diagnostic that maps each stuck state to a real cause.
7 min read
BGP vs OSPF: When to Use Each Routing Protocol
BGP and OSPF solve different problems and almost always run together in production. The technical differences, when each is the right answer, and the architecture pattern most enterprises end up with.
7 min read
BGP Path Attributes Explained: Well-Known vs Optional
BGP path attributes are the foundation of every traffic engineering technique: local preference, MED, AS-path prepending, communities. Understand the well-known vs optional attribute matrix before touching policy.
4 min read
BGP Message Types: OPEN, UPDATE, KEEPALIVE, and NOTIFICATION
BGP uses just four message types: OPEN, UPDATE, KEEPALIVE, and NOTIFICATION. Understanding the field-level format of each makes debug output and packet captures far more readable for anyone troubleshooting BGP.
4 min read