![Ticket#18 – Spanning Tree Topology Change Flood: Root Guard Protects Core Switch [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket18-–-Spanning-Tree-Topology-Change-Flood-Root-Guard-Protects-Core-Switch_networkjourney.png)
Problem Summary A large enterprise network started experiencing random connectivity drops across departments. Printers became unreachable, VoIP calls dropped, and some switches rebooted due to CPU spikes. On closer inspection, the Spanning Tree topology kept changing every few seconds. Logs across core switches showed constant […]
![Ticket#19 – DHCP Clients Getting APIPA Address: Troubleshooting DHCP Snooping and Relay Agent Issues [CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket19_DHCP-Clients-Getting-APIPA-Address-Troubleshooting-DHCP-Snooping-and-Relay-Agent-Issues_networkjourney.png)
Problem Summary A new VLAN was added for a temporary training lab. Clients connected successfully but were not receiving IP addresses from the DHCP server. Instead, they self-assigned APIPA addresses (169.254.x.x), making them unable to reach the internet or internal resources. Initial pings to the […]
![Ticket#20 – Default Route Not Propagating in BGP: Missing Network Statement Fixed [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket20_Default-Route-Not-Propagating-in-BGP_Missing-Network-Statement-Fixed_networkjourney.png)
Problem Summary In a multi-site enterprise setup running eBGP, the edge router was configured with a static default route pointing to the internet. However, this default route was not being advertised to downstream routers via BGP. Remote sites relied on the HQ BGP router to […]
![Ticket 21: Wireless Clients Disconnect Randomly: FlexConnect Central Switching Misconfigured[CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket21_-Wireless-Clients-Disconnect-Randomly-FlexConnect-Central-Switching-Misconfigured_networkjourney.png)
Problem Summary A branch site reported that multiple wireless clients were randomly disconnecting. This issue affected different SSIDs and was reported during peak business hours. There were no recent code upgrades or changes (at least none that the local IT admitted. Symptoms Observed Root Cause […]
![Ticket#22: Access Switch High CPU – Excessive SNMP Polling Detected [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket22-Access-Switch-High-CPU-–-Excessive-SNMP-Polling-Detected_networkjourney-1.png)
Problem Summary A critical alert was triggered in the NMS dashboard reporting continuously high CPU (95–100%) on one access switch (Cisco Catalyst 2960X). The NOC team suspected a misbehaving script or faulty hardware. Symptoms Observed Root Cause Analysis Upon reviewing the environment and switch configs, […]
![Ticket#23: SSL VPN Users Cannot Reach Internal Resources – Split Tunnel ACL Error Fixed [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket23-SSL-VPN-Users-Cannot-Reach-Internal-Resources-–-Split-Tunnel-ACL-Error-Fixed_networkjourney.png)
Problem Summary Users working remotely via Cisco AnyConnect VPN reported that while the VPN connection establishes successfully, they are unable to access any internal servers, applications, or file shares (e.g., 10.10.0.0/16 or 192.168.1.0/24). Symptoms Observed Root Cause Analysis Upon investigating the ASA config and using […]
![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 […]
![Ticket#25: Server Reachable via Ping but Not SSH – TCP MSS Clamp Missing on Firewall [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket25_Server-Reachable-via-Ping-but-Not-SSH-–-TCP-MSS-Clamp-Missing-on-Firewall_networkjourney.png)
Problem Summary A remote branch server (e.g., 10.1.20.10) was reachable via ping, but users could not SSH or access HTTPS applications hosted on it. The server was behind a firewall that performed NAT and IPSec VPN termination. Symptoms Observed Root Cause Analysis On closer inspection, […]
![Wireless LAN Controller Architecture – A CCNP Deep Dive [CCNP ENTERPRISE]_networkjourney](https://networkjourney.com/wp-content/uploads/2025/07/Wireless-LAN-Controller-Architecture-–-A-CCNP-Deep-Dive-CCNP-ENTERPRISE.png)
If you’ve ever worked with enterprise Wi‑Fi, you know how vital a good controller architecture is. I remember troubleshooting a campus network where the WLC was overloaded and APs were floating—quite a nightmare! That’s exactly why today, we’re going to explore Wireless LAN Controller (WLC) […]
![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 […]
