Cisco BGP Troubleshooting: Essential Commands Every Network Engineer Should Know
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 …
Border Gateway Protocol (BGP): How the Internet’s Routing Protocol Works
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 …
Private vs. Public Autonomous System Numbers (ASN): What’s the Difference?
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 …
Power Cabling Do’s and Don’ts in a data center
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Patreon Post: Mikrotik tagging incoming routes with a community
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 …
IPv4 Subnet Mask Cheat Sheet: A Handy Guide
IPv4 Subnet Mask Cheat Sheet CIDR Notation Subnet Mask Total Subnets Hosts per Subnet (usable) /8 255.0.0.0 1 16,777,214 /9 255.128.0.0 2 8,388,606 /10 255.192.0.0 4 4,194,302 /11 255.224.0.0 8 2,097,150 /12 255.240.0.0 16 1,048,574 /13 255.248.0.0 32 524,286 /14 …
Understanding the Types of Power in a Data Center
A data center is the beating heart of modern businesses, housing critical IT infrastructure that powers applications, processes, and data. Behind this infrastructure lies a robust power system designed to ensure uninterrupted operation. Power systems in a data center are …
What is the Global BGP Routing Table?
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.
How Does TCAM Work in Routers?
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 …
Data Center physical security
Physical security in a data center is critical as it serves as the first line of defense against unauthorized access, vandalism, theft, and environmental threats. Here’s a deeper dive into the various layers and strategies involved in ensuring comprehensive physical …
Overview of OSPF and BGP Differences and why
Having done consulting for years I saw many instances where BGP, especially ibgp, was used where OSPF would have been a better fit. Sometimes, this was for a specific reason; sometimes, it was just not knowing better. I am from …
Why BGP is the Backbone of the Internet: Understanding the Importance of Border Gateway Protocol
The Internet, as we know it today, is a vast network of interconnected systems that allow seamless communication, data transfer, and access to information. But have you ever wondered how data finds its way across such a sprawling network? This …