Packets DownRange
Border Gateway Protocol (BGP) filtering is critical for securing and optimizing internet routing. Improper BGP configuration can lead to serious issues like route leaks, hijacks, or suboptimal routing. Here are the most effective best practices for BGP filtering: 1. Prefix Filtering Objective: Ensure only authorized prefixes are advertised or accepted. 2. AS-PATH Filtering Objective: Prevent … Read more
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When BGP (Border Gateway Protocol) misbehaves, the ripple effect can be massive—routes disappear, prefixes flap, and connectivity grinds to a halt. Whether you’re managing a large enterprise edge or an ISP core, knowing how to quickly diagnose BGP issues on Cisco routers is critical. Here’s a hands-on guide to the most useful Cisco IOS BGP … Read more
Border Gateway Protocol (BGP) is a protocol that makes the Capital I Internet run. It is the fundamental system that Internet Service Providers (ISPs) and large networks use to exchange reachability information and ensure data finds its way across the complex web of networks making up the global Internet. This post will demystify how BGP … Read more
*) bgp – added input.filter-community;*) bgp – fixed excessive CPU usage;*) bgp – fixed input.accept-community;*) bgp – fixed memory leak on receiving notify and closing session;*) bgp – improved performance on BGP input;
In the world of internet networking, Autonomous System Numbers (ASNs) play a crucial role in routing data efficiently between different networks. ASNs are unique identifiers assigned to Autonomous Systems (AS)—large networks or groups of IP addresses that operate under a single organization, such as ISPs, cloud providers, or large enterprises. However, not all ASNs are … Read more
This content is for Patreon subscribers of the j2 blog. Please consider becoming a Patreon subscriber for as little as $1 a month. This helps to provide higher quality content, more podcasts, and other goodies on this blog.To view this content, you must be a member of Justin’s Patreon Unlock with PatreonAlready a qualifying Patreon … Read more
The Global BGP Routing Table is a comprehensive database that contains all the IP address prefixes (routes), which are advertised by ASNs, and the associated paths to reach them across the internet.
Border Gateway Protocol (BGP) is an essential protocol for internet routing, enabling autonomous systems (AS) to communicate and exchange routing information. Mikrotik RouterOS Version 7 introduced significant enhancements to its BGP implementation, making it more powerful and versatile. This guide walks you through setting up a BGP peer using RouterOS Version 7. Prerequisites Before proceeding, … Read more
BGP (Border Gateway Protocol) is essential for dynamic routing in modern networks. MikroTik’s RouterOS version 7 introduces significant updates to BGP functionality, making it more efficient and flexible. This guide walks you through configuring BGP filters on MikroTik RouterOS v7 to manage route propagation effectively. Prerequisites Before diving into the configuration, ensure: Step 1: Access … Read more
A critical component of BGP’s functionality is the Autonomous System Number (ASN). But what exactly is an ASN, and why is it so important?
In a previous post, I asked if TCAM is still needed in modern routers. In this post, I will examine how TCAM works in routers and provide some more insight into TCAM. In a router, TCAM stores and processes rules for various functions. These rules are typically derived from: Steps for TCAM Lookup: Why Do … Read more