The big idea is to support the same IP address in multiple locations, but to NOT have fate-sharing, where a problem like a bridging loop and resulting broadcast storm at one site would take down the other site. That means we can’t just throw up a tagged VLAN link (trunk) between the DCs. Instead, we have to divide the L2 broadcast domain (the VLAN) into different L2 domains separated by a routed segment. This way we’ve created two failure domains that will not share fate.
It’s Not What You Say. It’s How You’re Heard.
· 3 minutes to read
Published · Updated
In written communication, technical people can sometimes come across as impolite. I see this on Slack (talking down), Twitter (the angry tweeter), in emails (blunt and terse), in blog comments (bitter sarcasm or pedantry), Hacker News discussions (aggressive confrontation), and other places IT builders gather online. Perhaps you, as just such a technical person, don’t […]
Free Networking Lab Images From Arista, Cisco, nVidia (Cumulus)
· 12 minutes to read
Published · Updated
Here’s my current list of no cost, minimal headache, easily obtainable networking images that work in a virtual lab environment such as EVE-NG or GNS3. My goal is to clearly document what these images are and how to obtain them, as this data is less obvious than I’d like.
Don’t Be Complex When Simple Will Do
· 4 minutes to read
Published · Updated
We love shiny things. Sometimes, we work with technologies not because our company needs them, but because we want to put new skills on our resumes. Sometime when faced with a problem, we’ll default to how we solved it last time, rather than analyzing the new situation to see what’s most appropriate. We care more than the business does at times, because our switches and our servers and our cloudy constructs become pets we cherish and teach tricks to so we can show off to others. Our designs become laws. This is the way.
You Can’t Think If You’re Always Thinking
· 3 minutes to read
Published · Updated
My mind brings revelations to the surface when I’m out in the woods hiking, biking, or running, as I rarely listen to media when I’m out there. (It’s the bears, you see. Gotta listen for those bears.) So, why don’t I create more quiet time for myself?
New Tech Skills In Two Hours
· 3 minutes to read
Published · Updated
How long does it take to learn a new skill? It’s like…a really long time, right? You never have that much time to learn whatever it is. Most people who learn new skills are dedicated super humans who put in 25 hour days doing labs and reading books and taking courses and sniffing markers. Those folks sacrifice everything to stay ahead and earn the tough certs. Right? Isn’t that how it’s supposed to work? Don’t overthink it.
Buying Used Cisco Gear From eBay For Your Lab
· 4 minutes to read
Published · Updated
While most of the lab work I do is with virtualized networking gear, once in a while, I need actual hardware. For instance, to fully explore QoS, hardware is key. Many QoS commands won’t be available to you in a virtual network device. eBay offers lots of older networking gear for pennies or even fractions of a penny of what the gear was worth new. Why so cheap? Mostly, older networking gear is too slow for modern LANs and WANs. That’s a win for learners who don’t care about the speed as long as they can still use the old box to learn the fundamentals of routing and switching. There are caveats to eBay networking gear, though, not unlike buying a used car. Know what you’re getting into.
Jassy’s Replacement At AWS Matters
· 11 minutes to read
Published · Updated
As Andy Jassy takes over the CEO role at Amazon, the question is asked, “Does it matter who takes over at AWS, the position Jassy is vacating?” The idea is that AWS is such a dominant force in public cloud, an untrained monkey could sit at the helm and AWS would continue printing billions of dollars. So who cares who replaces Jassy? Whoever the new human is, they can’t get it wrong. That might be exactly right, but for the thought exercise, I decided to go a different direction. For purposes of this opinion article, I choose to entertain the idea that Jassy’s replacement does matter, and matters a lot.