Have you ever heard about two new PoE enhancements that are available on some Catalyst 3850 and all Catalyst 9K platforms? If not, you’re not alone. I only found out about these few months back by accident when I was troubleshooting some issues. There are two great features available for you to configure on PoE-enabled switches:
Perpetual PoE: preserves power during warm reload
Fast PoE: provides power to the port after cold start at pre-outage levels
Hi chaps. Fisrt of all, I would like to apologize for lack of activity on this blog. The company where I work was hit by NotPetya ransomware last summer. As a result, we worked absolutely crazy hours for many months to recover all our services and secure our network. I simply had no spare time to contribute to this blog. Anyway, things are much more stable and steady now, so I will try to get back to my hobbies.
Today I would like to give you a brief overview of StackWise Virtual technology, which Cisco has introduced in Denali 16.3.3 IOS-XE.
Originally, only Catalyst 3850 48XS switching platform supported this feature. At the moment of writing of these notes, Cisco announced support of the feature across all Catalyst 9500 series.
If you have ever worked with Cisco ISR4K platform, you probably know that these routers have plenty of horsepower. That is, you will probably hit the licensed throughput limit before you even get to 50% on CPU. This can be very frustrating when you troubleshoot, because you need to know (a) platform’s throughput (b) current load. What I always hated is the fact that Cisco doesn’t make required information available to public. For example, the only document about ISR4K performance I found was classified as ‘Cisco Confidential’ and even that one lacked any information about troubleshooting guidelines. Anyway, I’ll keep this post short. Here’s the troubleshooting methodology I use (inc hidden commands I got from Cisco TAC). Continue reading →
It’s been a while since I’ve posted anything on my website. I had a crazy year, had a lot of work that ruined all my plans to study a lot. Hopefully it’s now sorted with my management and next year is promised to be much better from the work/life/study balance perspective. I know I wasn’t a best webmaster and didn’t respond to many of your comments – I promise I will improve and reply to all comments in the coming weeks. I am going for WISECURE exam in less than two weeks from now, so wish me luck.
In the meanwhile, I’d like to share an undocumented feature of Cisco Prime (well, at least I wasn’t able to find any guidelines on that in Cisco Prime documentation). I have recently configured Prime for images archiving, but few days later realized that it fails to copy images from Catalyst 3850 switches. All transfer modes have been failing – FTP, SFTP, SCP and TFTP. There are no settings in Prime that relate to SCP and SFTP (you can only enable/disable FTP and TFTP servers). I’ve done some research and found that for SCP downloads Prime is acting as a client. Therefore, Catalyst 3850/3650 switches must be SCP servers.
To enable SCP server on Catalyst 3850/3650 execute the following global configuration command:
ip scp server enable
Once applied, Prime will be able to archive IOS-XE images from Catalyst 3850/3650s. However, there is restriction. Cisco Prime cannot archive an image from Catalyst 3850 if it was installed using INSTALL mode. That is, when BIN package is unpacked into few separate files. Only BUNDLE mode is supported for archiving. Not great huh? Cisco does not recommend to use BUNDLE mode for image distribution on Catalyst 3850s, but at the same time Cisco Prime can’t archive image if it was distributed using recommended INSTALL mode.
Cisco Catalyst 3850 has become a next generation switching platform in our company. We have deployed these switches in a number of our offices recently. Apart from being a converged wired/wireless access platform, it fully supports Flexible NetFlow. Therefore, it was a logical step to begin using this neat feature at least on our branche core switches to improve monitoring capabilities and lessen troubleshooting efforts. I have faced a number of issues while I’ve been trying to configure FNF on the first switch to perform some testing. So… Continue reading →