This post will be of zero interest to anyone who doesn't need to create very large ACLs on HPE Comware switches. If you are normal, look away now. I had a need to understand the ACL scaling limits on HP5130 switches. ACLs elsewhere on the network consist of a handful of rules to permit/deny specific... Continue Reading →
I've read the discussions over the last half a decade that Cisco's grip on the certification market, and the grip of certification on the job market, has dwindled. I believed what people were saying that such traditions had been replaced by a broader vendor outlook from employers together with the requirement to demonstrate broader skills... Continue Reading →
Intro: Broadcast Loops v Broadcast Storms Wherever there is a broadcast domain there exists the opportunity for some idiot to create a loop. It happens in the simplest of environments where a misunderstanding or mis-configuration creates a logical loop where BUM traffic (broadcast, unknown-unicast, multicast) is allowed to go round and round like a merry-go-round.... Continue Reading →
This post is a copy of the content at https://constantpinger.github.io/github/GH_pages.html This is the first page written within GitHub Pages and falls around the 4 hour point in the journey to understanding the technology. Upon hearing about the concept I thought this would be a brilliant way to produce content about code I've written or tech... Continue Reading →
Raritan calls this the Command Line Protocol (CLP) interface and the manual states “enables data center administrators to perform some basic management tasks”. They aren’t joking when they say basic. Here is what they state: Reset the Dominion PX deviceDisplay the name, power state (on or off), and sensors associated with each outletTurn each outlet... Continue Reading →
Every vendor has their favourite format for MAC addresses and it is common to need to create strings to pass as CLI commands. This post shows to check the string is a valid address and how to convert between formats. If you run HPE/Aruba switches the discussion on custom formats will be useful. The python... Continue Reading →
How to change the format of MAC address strings in Ansible.
I love uniformity. I see a collection of engineered objects (switch configs, shelves, rows of seedlings) as perfect when they are all the same. If they aren't the same then by definition some must be sub-standard. Also if they are uniform then something magical happens. You only have one state to consider/tweak/monitor etc. You know... Continue Reading →