![Ticket#14 - OSPF Routes Missing: Area Type Mismatch (Stub vs NSSA) Fixed [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket14_OSPF-Routes-Missing-Area-Type-Mismatch-Stub-vs-NSSA-Fixed_networkjourney.png)
Problem Summary An enterprise network running OSPF faced missing routes in one part of the topology. The issue was traced to an OSPF area type mismatch — one router was configured as a Stub area, while its neighbor was configured as NSSA (Not-So-Stubby Area). This […]
![Ticket#13: VLAN Not Propagating Across Switches – VTP Revision Number Conflict Fixed [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket13_VLAN-Not-Propagating-Across-Switches-–-VTP-Revision-Number-Conflict-Fixed_networkjourney.png)
Problem Summary In an enterprise campus network, a new switch was added to the core distribution layer. After connecting it to the existing VTP domain, several VLANs disappeared across the access layer. This triggered a major network outage affecting voice, data, and Wi-Fi. Symptoms Observed […]
![Ticket#12: High Packet Loss on WAN Link – Diagnosing QoS Misconfigurations [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket12_High-Packet-Loss-on-WAN-Link-–-Diagnosing-QoS-Misconfigurations_networkjourney.png)
Problem Summary A branch office reported high packet loss and poor application performance over the WAN. The issue impacted VoIP calls, Citrix sessions, and file transfers, despite the link being stable. Symptoms Observed Example CLI Output: Root Cause Analysis On investigation, engineers found: Root Cause: […]
![Ticket#11: BGP Neighbor Flap – Hold Timer Expiry Due to MTU Mismatch [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket11_BGP-Neighbor-Flap-–-Hold-Timer-Expiry-Due-to-MTU-Mismatch_networkjourney-1.png)
Problem Summary An enterprise experienced intermittent BGP neighbor flaps between core and WAN routers. The problem began after a WAN upgrade to a new service provider with slightly different interface MTU defaults. Symptoms Observed Root Cause Analysis After deeper analysis using packet captures and interface […]
![Ticket#15 - Multicast Video Freezes Randomly: PIM DR Election Misconfiguration Found [CCNP Enterprise]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket15_Multicast-Video-Freezes-Randomly_PIM-DR-Election-Misconfiguration-Found_networkjourney-1.png)
Problem Summary In a large campus network using multicast video for digital signage and corporate streaming, users began reporting intermittent video freezing across multiple access switches. The issue was not tied to any specific time, user, or content, and only affected a subset of devices […]
![Ticket#16 – SD-WAN VPN 0 Down: Color Mismatch Between Transport Interfaces [CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket16-–-SD-WAN-VPN-0-Down_Color-Mismatch-Between-Transport-Interfaces_networkjourney-1.png)
Problem Summary A new remote branch router was provisioned and onboarded using Cisco vManage. However, post boot-up, it failed to bring up any IPsec tunnels over VPN 0. The remote site couldn’t reach data center applications, even though the WAN link was physically UP and […]
![Ticket#17 – VoIP Choppy Audio During Peak Hours: DSCP Marking Not Trusted on Switch Ports [CCNP ENTERPRISE]](https://networkjourney.com/wp-content/uploads/2025/07/Ticket17-–-VoIP-Choppy-Audio-During-Peak-Hours-DSCP-Marking-Not-Trusted-on-Switch-Ports_networkjourney.png)
Problem Summary A growing organization reported that VoIP call quality degraded during peak business hours. Users experienced broken audio, dropped syllables, and poor call clarity. This issue was only observed when the network was under load—especially during data backups or heavy file transfers between branches. […]
![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 […]
