![Ticket#24: Routing Table Blackhole – Route Redistribution Loop Detected Between OSPF and BGP [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket24_Routing-Table-Blackhole-–-Route-Redistribution-Loop-Detected-Between-OSPF-and-BGP_networkjourney.png)
Problem Summary An enterprise site experienced sporadic loss of connectivity to external services and some internal prefixes. The issue appeared after a change request to redistribute OSPF into BGP and vice versa at the WAN edge. Symptoms Observed Example output: Root Cause Analysis The team […]
![CAPWAP Overview – Bridging Access Points and Controllers [CCNP Enterprise] _networkjourney](https://networkjourney.com/wp-content/uploads/2025/07/CAPWAP-Overview-–-Bridging-Access-Points-and-Controllers-CCNP-Enterprise.png)
If you’ve ever wondered how your lightweight Access Points (APs) talk seamlessly to the Wireless LAN Controller (WLC) behind the scenes, then you’re about to get clarity. Trust me—when I first began working with wireless deployments, I was equally intrigued by how these APs automatically […]
![Don’t Let Your Router Crash! Master Control Plane Policing (CoPP) with Labs & CLI [CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/nj-blog-post-CoPP.jpg)
Ever had one of those moments where your device just locks up, and you can’t even SSH or ping it anymore—even though the CPU is not maxed out? I’ve been there. As someone who’s spent years deep in the trenches of data centers and campus […]
![Want to Stop Unauthorized Access? SSH and HTTPS Hardening Explained[CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/nj-blog-post-ssh-https.jpg)
when was the last time you audited your device’s remote access methods?I still remember the day when a client called me in panic—someone had brute-forced their router via SSH, and guess what? The router had no access-lists, no username policy, and was running outdated SSHv1. […]
![Mastering DHCP Snooping and Binding Table: Secure Your Layer 2 Network Like a Pro [CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/nj-blog-post-dhcp-snooping-binding-table.jpg)
I’ve had this discussion countless times with my students — “What if someone plugs in a rogue DHCP server and hijacks the IP allocation process?” Trust me, this isn’t just a theoretical concern. In modern LAN environments like shared offices, college campuses, and enterprise floors, […]
![Route Maps vs Prefix Lists – A Deep Dive for Real-World Networking [ CCNP ENTERPRISE ]_networkjourney](https://networkjourney.com/wp-content/uploads/2025/06/Route-Maps-vs-Prefix-Lists-–-A-Deep-Dive-for-Real-World-Networking-CCNP-ENTERPRISE-.png)
If you’ve ever sat there staring at your router’s CLI wondering whether to use a route map or a prefix list, you’re not alone. I’ve seen many students — even working professionals — struggle with this subtle yet powerful decision. Today, I’ll walk you through […]
![Routing Table Lookup Process – Explained with Lab & CLI [ CCNP ENTERPRISE ]_networkjourney](https://networkjourney.com/wp-content/uploads/2025/06/Routing-Table-Lookup-Process-–-Explained-with-Lab-CLI-CCNP-ENTERPRISE-.png)
Today I’m going to deep-dive into a very important yet often overlooked concept – the Routing Table Lookup Process. Many of my students know how to configure OSPF, BGP, or EIGRP, but when asked “How does a router actually choose the best route when multiple […]
![Mastering Layer 2 Troubleshooting Commands: A Complete Guide with CLI & EVE-NG Labs [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/06/Mastering-Layer-2-Troubleshooting-Commands_networkjourney.png)
Today we’re diving into something every network engineer must master—Layer 2 Troubleshooting. Whether you’re preparing for CCNP or resolving critical enterprise network issues, knowing the right CLI commands can make all the difference. In this post, we’ll walk through key Layer 2 concepts, explore essential […]
