Redundancy Is Not Resiliency | The Networking Nerd

Most individuals carry a spare tire of their automobile. It’s there in case you get a flat and wish to vary the tire earlier than you might be in your method once more. In my previous VAR job I drove loads away from residence and to the center of nowhere so I didn’t wish to depend on roadside help. As a substitute I simply grabbed the additional tire out of the again if I wanted it and went on my method. Nonetheless, the method wasn’t totally hitless. Even the pit crew for a racing group wants time to vary tires. I might most likely get it executed in 20 minutes with acceptable cursing however these have been 20 minutes that I wasn’t doing anything past fixing a tire.

Spare tires are redundant. You have got an additional factor to interchange one thing that isn’t working. IT operations groups are accustomed to redundant programs. Perhaps you’ve gotten a chilly spare on the shelf for a change which may go down. You might need a chilly or heat knowledge heart location for a catastrophe. You possibly can even have redundant gadgets in your enterprise that can assist you get again in to your gear if one thing causes it to go offline. Properly, I say that you simply do. When you’re Meta/Fb you didn’t have them this time final yr.

Don’t mistake redundancy for resilience although. Just like the tire analogy above you’re not going to have the ability to repair a flat when you’re driving. Sure, I’ve seen the loopy video on-line of individuals doing that however except for stunt driving you’re going to must take some downtime out of your journey to repair the tire. Likewise, a redundant setup that features chilly spares or out-of-band gadgets which might be linked on to your community might incur downtime in the event that they go offline and lock you out of your administration system. Fb most likely thought their out-of-band management system labored simply high quality. Till it didn’t.

The Proper Gear for Resilience

At Networking Discipline Day 29 final week we have been lucky to see Opengear current once more for the second time. I’m accustomed to them from all the way in which again at Networking Discipline Day 2 in 2011 so their journey by means of the modifications of networking over the previous decade has been nice to see. They make out-of-band gadgets they usually make them nicely. They’re one of many firms that instantly spring to thoughts when you consider options for gaining access to gadgets exterior the traditional community entry methodology.

As a VAR there have been occasions that I wanted to make calls to places with a purpose to reboot gadgets or get console entry to repair a difficulty. Whether or not it was driving 3 hours to press F1 to clear a failed energy provide message or racing throughout city to revive cellphone service after locking myself out of an SSH session there are quite a few the explanation why having precise bodily entry to the console is necessary. Till we excellent quantum teleportation we’re going to have to resolve that drawback with know-how. Right here’s a video from the Networking Discipline Day session that highlights a number of the challenges and options that Opengear has out there:

Ryan Hogg brings up a terrific argument right here for redundancy versus resiliency. Are you managing your gadgets in-band? Or do you’ve gotten a devoted administration community? And what’s your backup for that devoted community if one thing goes offline? VLAN separation isn’t ok. Within the occasion of a failure mode, comparable to a bridging loop or one other assault that takes a change offline you gained’t be capable to entry the administration community if you happen to can’t despatched packets by means of it. If the tire goes flat you’re stopped till it’s mounted.

Opengear solves this drawback in various methods. The primary is after all offering a secondary entry methodology to your community. Opengear console gadgets have a mobile backup operate that may assist you to entry them within the occasion of an outage, both from the inner community or from the Web taking place. I can consider a few occasions in my profession the place I might have liked to have been ready to connect with a mobile interface to undo a change that simply occurred that had unintended penalties. Typically reload in 5 doesn’t fairly do the job. Having a dependable method to connect with your core gear makes life simple for community working programs that don’t maintain from making errors.

Nonetheless, as talked about, redundancy shouldn’t be resiliency. It’s not sufficient for us to have entry to repair the issue whereas every part is down and the world is on hearth. We could possibly get again in and repair the difficulty without having to drive to the location however the customers in that location are nonetheless down whereas we’re working. SD-WAN gadgets have supplied us numerous connectivity choices for various years now. If the primary broadband line goes down simply fail again to the mobile connection for vital visitors till it comes again up. Straightforward to do now that we have now the right gear to create circuit range.

As outlined within the video above, Opengear has the identical functionality as nicely. When you don’t have a flowery SD-WAN edge system you’ll be able to nonetheless configure Opengear console gadgets to behave as a secondary egress level. It’s so simple as configuring the community with an IP SLA to trace the state of the WAN hyperlink and putting in the mobile route within the routing desk if that hyperlink goes down. As soon as configured your customers can get out on the backup hyperlink when you’re coming in to repair no matter precipitated the difficulty. If it’s the ISP having the difficulty you’ll be able to log a ticket and make sure issues are working on-site with out having to leap in a automobile to see what your customers see.

Resilience Actually Issues

One of many issues that Opengear has at all times impressed me with is their litany of use circumstances for his or her gadgets. I can already consider a ton of ways in which I might implement one thing like this for patrons that want monitoring and resilient connectivity choices. Distant places of work are an apparent selection however so too are places with horrible connectivity choices.

If you’re working in a location with spotty connectivity you’ll be able to simply deploy an Opengear system to keep watch over the community and/or servers in addition to offering an additional method for the location to get again on-line within the occasion of a difficulty. If the WAN circuit goes down you’ll be able to simply jump over to the mobile hyperlink till you get it mounted. Opengear will inform you one thing occurred and you’ll log into the Lighthouse central administration system to go there and gather knowledge. If configured accurately your customers could not even understand they’re offline! We’re nearly on the level of fixing the tire whereas we’re driving.

Tom’s Take

I’m usually requested if I miss engaged on networking gear since I hardly ever contact it lately. As quickly as I’m compelled to reply that query I bear in mind all of the occasions I needed to drive someplace to repair a difficulty. Wasted time can by no means be recovered. Sources value cash whether or not it’s cash for a tool or time spent going to repair one. I take a look at the capabilities that an organization like Opengear has right now and I want I had these fifteen years in the past and will deploy them to locations I do know wanted them. In my former line of labor redundant issues have been laborious to return by. Resilient choices have been rather more interesting as a result of they supplied greater than only a again plan in case of failure. That you must choose resiliency each time as a result of in any other case you’re going to be shedding time changing that tire when you could possibly be rolling alongside fixing it as an alternative.


Opengear was a presenter at Networking Discipline Day 29 on September 7, 2022. I’m an worker of Tech Discipline Day, which is the corporate that managed the occasion. This weblog put up represents my very own private ideas in regards to the presentation and isn’t the opinion of Tech Discipline Day. Opengear didn’t present compensation for this put up or ask for editorial approval. This put up is my perspective alone.


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