BGP

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.

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BGP Field Reference (9-Page Printable Cheat-Sheet)

Nine printable pages of BGP: the neighbor state machine, the 13-step path selection algorithm, the major path attributes side by side, AS-path regex patterns, and the commands to type when an adjacency sticks in OpenSent.

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.

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.

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.

Featured

What Is BGP? The Protocol That Runs the Internet

Every time you load a webpage, your traffic crosses networks owned by different organizations. BGP, the Border Gateway Protocol, is what stitches 75,000+ autonomous systems into a single working internet. Here is how, and why.

BGP Route Filtering with Prefix Lists

Prefix lists are the preferred BGP filtering tool: faster than ACLs, easier to read, and built for matching networks with specific prefix lengths. Every production BGP deployment needs them on inbound and outbound.