How Cisco 9800 Always-On Tracing Simplifies Wireless Issue Resolution

Hey there! The Cisco Catalyst 9800 Series Wireless LAN Controllers (WLCs) are pretty awesome, and one cool trick up their sleeve is the Always-On Tracing feature. It’s a total lifesaver for figuring out what’s going wrong in your wireless network. Let’s break it down quick—what it is, how it works, and why you’ll love it!

What’s Always-On Tracing?

Alright, so Always-On Tracing is built into the 9800 Series WLCs, running on Cisco IOS-XE. Forget the old-school way of turning on debugs and hoping the issue pops up again. This thing’s always running, logging key stuff to buffers so you can check out problems after they happen—no need to replay the chaos!

It’s perfect for those annoying, random issues like clients not connecting or access points (APs) acting up. You can look back hours or even days, depending on the logs, and get to the bottom of things fast.

How’s It Work?

The 9800 WLCs use a Linux-based setup with processes handling stuff like CAPWAP, mobility, and RRM. Here’s the quick rundown:

• Always Logging: It’s capturing errors and notices 24/7—no manual setup needed.
• Separate Buffers: Each process has its own log, so it’s super organized.
• Look Back Anytime: Client fails to connect? Check the logs, no do-overs required.
• Syslog Bonus: Send logs to a syslog server for extra storage.
• Grab the Data: Hop on via SSH and run show logging profile wireless filter mac <Client_MAC> to-file always-on-<FILENAME.txt> to save logs for a client.

Why It’s Awesome

• No Repeat Needed: Issues don’t have to happen again—just check the logs!
• Saves Time: Find the problem fast—misconfigs, auth fails, you name it.
• Clear View: Tons of detail on what’s going on with clients, APs, and more.
• Works Everywhere: From small setups to huge ones, it’s got you covered.

Quick Example: Client Won’t Connect

Say a client (MAC: e4b3.187c.3058) can’t join the network. No sweat! Here’s what to do:

1. Run show clock to check the time.
2. Use show logging profile wireless filter mac e4b3.187c.3058 to-file always-on-fail.txt for logs.
3. Look for Errors (ERR) like [epm-acl] [8104]: (ERR): ACL acl-sent-by-ise is missing.
4. Check syslog or share with Cisco TAC if you’re stuck.

Using the Cisco Wireless Debug Analyzer

Want to level up? The Cisco Wireless Debug Analyzer is your new best friend! This cloud-based tool, helps you make sense of those Always-On Tracing logs. Here’s a quick how-to:

• Get Your Logs: Grab your Always-On Tracing output with a command like show logging profile wireless filter mac <Client_MAC> to-file always-on-<FILENAME.txt>.
• Upload to the Tool: Head to the Cisco Wireless Debug Analyzer, and upload your log file.
• Instant Insight: It parses the logs, spots issues like auth failures or AP join problems, and gives you easy-to-read results—super fast!
• Fix It: Use the tool’s tips to tweak configs or dig deeper. It’s like having a pro in your pocket!

Pair this with Always-On Tracing, and you’re troubleshooting like a champ in no time!

Quick Tips

• Send logs to a syslog server to keep ‘em safe.
• Filter with show logging profile wireless filter mac <Client_MAC> to-file always-on-<FILENAME.txt> to stay focused.
• Watch log volume — busy networks fill buffers fast!

Wrap-Up

Always-On Tracing on the Cisco Catalyst 9800 WLCs is a total game-changer. It’s always watching, so you can fix issues fast without breaking a sweat. Perfect for any network, big or small! Get started today!