Look, I get asked this question constantly in my training sessions: “Why should I bother learning network automation when I can just SSH into my devices?” And honestly, if you’re still thinking that way in 2024, you’re missing the point entirely and Cisco pyATS is the answer.
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I’ve been teaching networking for years now, and I watch engineers struggle with the same problems over and over. They spend their weekends manually checking hundreds of devices after a change. They miss critical issues because they can’t possibly verify everything manually. Then they wonder why their networks aren’t as reliable as they should be.
Network automation isn’t about replacing what you do – it’s about doing what you do better, faster, and with fewer mistakes. And pyATS? Well, it’s the tool that finally gets network automation right.
Why Manual Network Management Doesn’t Work Anymore
Remember when you could manage 50 routers by logging into each one individually? Those days are over. I was working on a network recently with over 2,000 devices, and the customer was still trying to manage everything manually. Want to guess how that was going?
Their change windows took 8 hours because they had to verify each device individually. Half the time they’d miss something and have to go back. And don’t get me started on their documentation – it was months out of date because nobody had time to keep it current.
That’s not sustainable. Modern networks are too big, change too frequently, and have too many interdependencies for manual management.
The Real Problems You Face Every Day
Let me tell you what I see in every organisation I work with:
Configuration Drift You configure device A one way, then device B slightly differently because you learned something new or had to work around an issue. Before you know it, every device is configured differently. Good luck troubleshooting that mess.
I worked with a bank where they had 200 switches, and no two were configured exactly the same way. They spent more time figuring out why each device was different than actually fixing problems.
Human Mistakes We all make them. I’ve shut down the wrong interface more times than I care to admit. You probably have too. The difference is that when you’re working manually, those mistakes happen in production during critical changes.
Can’t Keep Up with Scale Your network keeps growing, but your team doesn’t. You can’t hire engineers fast enough to manually manage everything. So what happens? Things slip through the cracks. Problems go unnoticed until users complain.
Inconsistent Troubleshooting When something breaks at 2 AM, different engineers approach the problem differently. Some check interfaces first, others look at routing tables. There’s no systematic approach, so you miss things and take longer to resolve issues.
What Network Automation Actually Means
Most people think automation is just pushing configurations to devices. That’s part of it, but it’s not the important part.
Real network automation is about validation. It’s about knowing that your network is actually working the way you designed it to work.
Configuration Management
Yes, you can push configs automatically. But more importantly, you can ensure they’re applied correctly and consistently. You can version control them, roll them back if needed, and track exactly what changed when.
Network Testing and Validation
This is where it gets interesting. Instead of assuming your OSPF adjacencies are up, you test them automatically. Instead of hoping your BGP routes are being advertised correctly, you verify them systematically.
I worked with an ISP that was manually checking BGP tables on 500 routers every time they made a change. It took hours. Now they run automated tests that verify everything in minutes and catch issues they would have missed manually.
Monitoring That Actually Works
Forget simple SNMP polling. Real monitoring understands your network protocols, tracks performance trends, and alerts you about problems before they affect users.
Living Documentation
Documentation that updates itself as your network changes. No more outdated diagrams or incorrect IP address spreadsheets.
Systematic Incident Response
When things go wrong, you need to gather information quickly and consistently. Automation ensures you collect the right data every time without missing anything important.
Why Traditional Automation Tools Miss the Mark
Ansible, Puppet, Chef – they’re great for servers. But networks are different.
With servers, you install software, copy files, start services. It’s straightforward. With networks, configuration is just the beginning. The real question is whether your network is actually doing what you configured it to do.
Let’s say you configure OSPF on a router. Ansible can push the configuration, but can it tell you if the neighbour relationships formed correctly? Can it verify that routes are being exchanged? Can it detect if convergence is taking too long?
No. Because those tools weren’t built for networks.
I’ve seen organisations spend months trying to make Ansible work for network validation. They end up writing hundreds of lines of custom playbooks with terrible error handling, and it still doesn’t work properly.
Why Cisco pyATS Changes Everything
pyATS was built specifically for network testing. Not adapted from server automation – built from scratch for networks.
Works with Multiple Vendors
You can test Cisco, Juniper, Arista, and other devices using the same framework. No more writing separate scripts for each vendor platform.
Understands Network Protocols
pyATS includes parsers for thousands of network commands. Instead of writing regular expressions to parse “show ip route” output, you get structured data you can actually work with.
Actually Works in Production
Cisco uses pyATS internally. This isn’t some lab toy – it handles real networks with thousands of devices.
Focuses on Testing
Cisco pyATS encourages you to write tests first, then make changes. You define what “working correctly” means, then verify your network meets those criteria.
Proper Reporting
When tests fail, you get detailed logs showing exactly what went wrong. No more guessing or digging through CLI output trying to figure out what happened.
Real Examples from Networks I’ve Worked On
Let me share some actual experiences rather than made-up success stories.
Large Service Provider Router Upgrade Customer needed to upgrade IOS-XR on 200 edge routers. Traditionally, they’d create detailed procedures, test on a few devices, then roll it out during maintenance windows hoping nothing broke.
Instead, we built pyATS tests that captured the complete state before changes – routing tables, interface status, BGP neighbours, everything. After each upgrade, we ran the same tests to verify nothing was broken.
Result? We caught three routers that didn’t come back up properly after the upgrade, and two that had BGP neighbour issues. Without automated testing, those would have caused customer outages.
Financial Services Compliance Bank needed to verify that all network devices complied with security policies. Manual auditing took weeks and was error-prone.
We created automated compliance tests that ran nightly. Tests checked access lists, interface security, routing protocol authentication – all the stuff that’s tedious to check manually.
Now they catch policy violations the same day they occur instead of during annual audits. And the auditors love the detailed reports.
Data Centre Migration Company was moving from physical to virtual infrastructure. They needed to ensure connectivity and performance remained consistent throughout the migration.
We built tests that continuously verified connectivity between old and new environments, checked routing was working correctly, and monitored performance metrics.
Migration finished two weeks early because we caught and fixed issues immediately instead of discovering them after users complained.
Understanding the Cisco pyATS Toolkit
pyATS isn’t just one tool – it’s a complete testing ecosystem.
AEtest Framework
The core testing engine. Handles test setup, execution, and cleanup. Makes your tests reliable and repeatable.
Genie Library
Contains parsers for network commands and data models for network features. This is what makes Cisco pyATS network-aware instead of just a generic automation tool.
Testbed Management
Describes your network topology and device connections. Works with physical networks, virtual labs, or mock devices for development.
Job Orchestration
Runs multiple tests across multiple devices in parallel. Collects results and generates comprehensive reports.
Advanced Features
Triggers and verifications for complex testing scenarios. Network state snapshots for before/after analysis. Device cleanup automation. Low-code testing with YAML.
Why This Matters for Your Career
Understanding automation isn’t optional anymore. It’s becoming a basic requirement for network engineering roles.
Risk Management
Automated testing reduces the risk of change-related outages. When you can validate changes before they impact users, you become much more valuable to your organisation.
Efficiency
Tasks that take hours manually can be completed in minutes with automation. You spend less time on repetitive work and more time on strategic projects.
Consistency
Automated processes work the same way every time. No variation based on who’s doing the work or what time of day it is.
Scalability
As networks grow, manual processes become impossible. Automated testing scales much better than hiring more people.
Career Advancement
Engineers who understand automation tools advance faster than those who don’t. It’s not just about technical skills – it’s about being able to solve business problems efficiently.
Common Pushback I Hear
Every time I teach Cisco pyATS, I get the same objections. Let me address them:
“Our network is too complex for automation”
Wrong. Complex networks need automation more than simple ones. The more complex your network, the more likely you are to miss something manually.
“We don’t have time to learn new tools”
You don’t have time not to learn them. The industry is moving toward automation whether you like it or not. You can learn now or get left behind.
“Manual processes work fine”
No, they don’t. You’ve just gotten used to the problems. Slow deployments, inconsistent results, missed issues – that’s not “fine.”
“Automation will eliminate networking jobs”
Automation eliminates repetitive tasks, not engineering jobs. Engineers who embrace automation become more valuable, not less valuable.
Getting Started the Right Way
Don’t try to automate everything at once. Start small and build your skills gradually.
Begin with Simple Tests
Test basic connectivity or interface status. Get comfortable with the tools before tackling complex scenarios.
Use Mock Devices
Practice with simulated devices before working on production networks. Cisco pyATS includes mock devices specifically for learning.
Focus on Validation First
Learn to test existing network functionality before trying to automate changes. Understanding validation is more important than configuration management.
Document Everything
Keep notes as you learn. Build a library of useful patterns and common solutions.
Start in Lab Environments
Perfect your skills in non-production environments. Make mistakes where they won’t affect users.
What You’ll Gain
After working with Cisco pyATS for a while, you’ll approach networking differently. Instead of reacting to problems, you’ll prevent them. Instead of hoping changes work, you’ll know they work because you’ve tested them.
You’ll spend less time on repetitive tasks and more time on interesting engineering challenges. Your networks will be more reliable because you’ll catch issues before they impact users.
Most importantly, you’ll have skills that make you more valuable in the job market. Network automation expertise is in high demand and short supply.
Moving Forward
In the next post, we’ll explore NetDevOps principles and how test-driven development applies to network operations. You’ll learn how to shift from reactive troubleshooting to proactive validation.
The journey from manual network management to automated testing isn’t just about learning new tools. It’s about changing how you think about network operations. pyATS gives you the framework to make that change successfully.
Your users expect reliable networks. Your business expects efficient operations. Your career depends on staying current with industry trends. pyATS helps you deliver on all three.
Start learning now. Every day you wait is another day you’re falling behind the curve.
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