![[Day #59 PyATS Series] Detect Split-Horizon Issues in Large Networks Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-59-PyATS-Series-Detect-Split-Horizon-Issues-in-Large-Networks-Using-pyATS-for-Cisco.png)
Introduction — key points Split-horizon and related route-advertisement problems are subtle but catastrophic in large networks: routes sometimes don’t propagate where they should, or — worse — are advertised back like a boomerang creating loops. Detecting these issues at scale requires automation, consistent evidence (raw […]
![[Day #62 Pyats Series] Building device health dashboard using Flask + pyATS using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Building-device-health-dashboard-using-Flask-pyATS-using-pyATS-for-Cisco.png)
Introduction on the Key Points Welcome back to Day 62 of the 101 Days of pyATS Series! Today, we’re diving into something that makes every network engineer’s life easier — a real-time device health dashboard built using Flask + pyATS for Cisco devices. Whether you’re […]
![[Day #40 PyATS Series] Identify Duplicate IPs in ARP Table Across Vendors Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-40-PyATS-Series-Identify-Duplicate-IPs-in-ARP-Table-Across-Vendors-Using-pyATS-for-Cisco-Python-for-Network-Engineer.png)
Introduction on the Key Points Duplicate IP addresses are one of the most common yet frustrating issues network engineers face in multi-vendor environments. They cause intermittent connectivity issues, ARP flapping, MAC address instability, and even network outages if not detected early. As a Python for […]
![[Day #38 PyATS Series] CPU & Memory Utilization Monitoring Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-38-PyATS-Series-CPU-Memory-Utilization-Monitoring-Using-pyATS-for-Cisco-Python-for-Network-Engineer.png)
Introduction Monitoring CPU and memory utilization is crucial for ensuring optimal network device performance and avoiding outages. High CPU or memory usage can indicate problems like excessive traffic, misconfigured processes, or hardware limitations. Traditionally, engineers manually check each device using CLI commands, which is tedious […]
Introduction Interface MTU (Maximum Transmission Unit) mismatches are a common cause of packet drops and network performance degradation. Identifying and resolving MTU mismatches across a multi-vendor environment (Cisco, Arista, Palo Alto, Fortinet) ensures consistent communication and avoids fragmentation issues. In this 101 Days of pyATS […]
![[Day #41 PyATS Series] Validate Routing Table Entries Across Cisco/Arista/Palo Alto/Fortigate Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-41-PyATS-Series-Validate-Routing-Table-Entries-Across-Cisco-AristaPalo-AltoFortigate-Using-pyATS-for-Cisco-Python-for-Network-Engineer.png)
Introduction on the Key Points Routing tables are the backbone of IP packet forwarding. Any mismatch, stale route, or missing entry can lead to packet drops, suboptimal routing, or even complete network outages. Traditionally, network engineers log in to each device and manually inspect the […]
![Day #49 PyATS Series] Check for Spanning-Tree Topology Changes (logs + CLI) using pyATS for Cisco](https://networkjourney.com/wp-content/uploads/2025/08/Day-49-PyATS-Series-Check-for-Spanning-Tree-Topology-Changes-logs-CLI-using-pyATS-for-Cisco.png)
Introduction — key points Spanning Tree Protocol (STP) topology changes — root bridge changes, port state transitions, flaps, and BPDU-related protections — are one of the most common causes of temporary outages and microbursts in switched networks. Detecting these events quickly and reliably across many […]
![[Day #33 PyATS Series] VRF Configuration Consistency Check Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-33-PyATS-Series-VRF-Configuration-Consistency-Check-Using-pyATS-for-Cisco-Python-for-Network-Engineer.png)
Introduction Maintaining Virtual Routing and Forwarding (VRF) configuration consistency is critical in multi-tenant or service provider networks. Misaligned VRF configurations can lead to routing leaks, traffic blackholing, and connectivity issues between VRF instances. Traditionally, network engineers manually log into each device to verify VRF names, […]
![[Day #32 PyATS Series] Tracing End-to-End Path (Multi-Hop Traceroute Validation) Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-32-PyATS-Series-Tracing-End-to-End-Path-Multi-Hop-Traceroute-Validation-Using-pyATS-for-Cisco-Python-for-Network-Engineer.png)
Introduction End-to-end path validation is a crucial part of network troubleshooting and performance analysis. Traceroute is one of the most widely used diagnostic tools to trace the path packets take across multiple hops in a network. However, manually running traceroute on individual devices and comparing […]
![[Day #31 PyATS Series] Detect VLAN Mismatches on Trunk Links Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-31-PyATS-Series-Detect-VLAN-Mismatches-on-Trunk-Links-Using-pyATS-for-Cisco.png)
Introduction Detecting VLAN mismatches on trunk links is crucial for maintaining seamless Layer 2 connectivity across a network. A VLAN mismatch can lead to traffic drops, inconsistent broadcast domains, and ultimately network instability. Traditional troubleshooting involves manually logging into each switch and comparing trunk configurations—a […]
