In the Cisco UCS servers, there are three classes or categories of Network Adapters for B-series and C-Server servers. I write this down because it’s pretty hard to find this summary anywhere is Cisco’s documentation and I keep having to tell people the difference. Now I can point them at this blog post.
Short version – I’d like you to read just these if nothing else.
- A data centre uses a lot of electricity. It’s dangerous.
- Just in case you didn’t pay attention – Electricity is really dangerous. Right, can we move on ?
- You should be scared of being electrocuted. That will keep you safe.
- When electrocution happens, the muscles in your limbs contract. This causes arms and hands to wrap around or clench objects.
- Someone who is being electrocuted can’t let go because of this
- If you touch a person being electrocuted, you will get an electric shock too, and may also be injured.
- The BEST thing to do is to turn the power off.
- Know where the power kill switch is for Data Centre. Or at least the breaker for the area that you are in.
- Don’t work in the Data Centre alone.
- Learn resuscitation. People who have been electrocuted are likely to have breathing problems and heart failure.
People shouldn’t die at work. Think seriously about going home everyday and what you can do to make that happen.
Quick tip on the best IP addresses on the Internet when you need to test your Internet connection from the command line
Most engineers think that cable is simply plug and play. And mostly, that true. In recent years, Ethernet standards and manufacturing Here are 20 things that Network Engineers have forgotten or don’t know about network cabling in a two part series on things I have learned in twenty years of looking after networks.
Define Threat Asymmetry
BPDU Guard and Root Guard are enhancements to Spanning Tree Protocol (STP) enhancements that improve the reliability of the protocol to unexpected events ad are primarily to ensure design enforcement ( integrity / security). There they must configured in specific locations in the networks.
When working on NX-OS it’s kind of annoying to attempt to use a feature that hasn’t been enabled and get an error message. Why not get an “not enabled” or “not licensed” error message ?
It’s a common discussion about when Cisco VTP protocol is actually forwarded through Cisco switches and when it’s isn’t. I’ve always gotten it somewhat confused and when I stumbled across some old notes on the topic I had an ah-hah moment. I’m answering the equation about when using VTP in your network, which versions are risky – that’s risky is terms of how do you prevent VTP updates from ‘crossing’ a switch.
Short Answer is “It depends, but usually yes.” Long answer follows with a discussion of launch power, receiver sensitivity, and cable losses.
I got asked a question by a reader “is OpenFlow used for Routing or Switching ?”