![[Day #57 PyATS Series] Change Management Validation for ACL Updates Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-57-PyATS-Series-Change-Management-Validation-for-ACL-Updates-Using-pyATS-for-Cisco.png)
Introduction — key points Access Control Lists (ACLs) are one of the most powerful — and risky — configuration constructs in a network. A misplaced line, wrong sequence number, or an overly-broad permit can either block business traffic or expose services. For any ACL change […]
![[Day #56 PyATS Series] Automating Pre/Post Config Change Checks (Brownfield) Using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-56-PyATS-Series-Automating-Pre_Post-Config-Change-Checks-Brownfield-Using-pyATS-for-Cisco.png)
Introduction on the key points When working in a brownfield network, every configuration change carries risk. You must verify what is there now (pre-check), apply a change under controlled conditions, and verify what changed (post-check). Doing this manually is slow and error-prone — especially across […]
![[Day#60 PyATS Series] Building Reusable Validation Libraries (Multi-Vendor) using pyATS [Python for Network Engineers]](https://networkjourney.com/wp-content/uploads/2025/08/Day-60-PyATS-Series-Building-Reusable-Validation-Libraries-Multi-Vendor-Using-pyATS-for-Cisco.png)
Introduction — key points As a network engineer moving into automation, one of the most valuable skills is creating reusable validation libraries: small, well-tested units (functions/classes) that encapsulate checks like “BGP neighbor up”, “interface up”, “ACL contains permit for X”, or “ospf adjacency count”. Reuse […]
![[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 #51 PyATS Series] Custom Parser for Unsupported Cisco/Arista/PaloAlto/Fortigate Commands using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Day-51-PyATS-Series-Custom-Parser-for-Unsupported-Cisco_Arista_PaloAltoFortigate-Commands-using-pyATS-for-Cisco.png)
Introduction — key points When automating network validation with pyATS and Genie you often rely on built-in parsers (device.parse(‘show …’)). But real networks contain vendor commands, feature flags, or platforms that Genie does not parse yet — or you have a bespoke command that prints […]
![[Day #46 Pyats Series] Validate QoS policy configurations using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Validate-QoS-policy-configurations-using-pyATS-for-Cisco.png)
Introduction on the Key Points Welcome to Day 46 of the 101 Days of pyATS (Vendor-Agnostic) series! In today’s lab-driven session, we’re focusing on validating QoS (Quality of Service) policy configurations using Cisco’s pyATS and Genie framework. Whether you’re managing enterprise WANs, campus LANs, or […]
![[Day #55 Pyats Series] Using Cisco/Arista/Paloalto/Fortigate with pyATS using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Using-CiscoAristaPaloaltoFortigate-with-pyATS-using-pyATS-for-Cisco.png)
Introduction on the Key Points As networks become increasingly hybrid and multi-vendor, vendor-agnostic automation becomes not just a good-to-have skill, but a must-have. Whether you’re working with Cisco routers, Arista switches, Palo Alto firewalls, or Fortigate appliances—your automation framework needs to talk to all of […]
![[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 #45 Pyats Series] Multi-vendor VRRP/HSRP failover validation using pyATS for Cisco [Python for Network Engineer]](https://networkjourney.com/wp-content/uploads/2025/08/Multi-vendor-VRRP-HSRP-failover-validation-using-pyATS-for-Cisco.png)
Introduction on the Key Points Welcome back to Day 45 of our “101 Days of pyATS” series, a practical journey into vendor-agnostic automation using Cisco’s pyATS framework! Today, we’re diving deep into failover validation for first-hop redundancy protocols (FHRPs)—VRRP and HSRP—using pyATS and Genie parsers. […]
