For the last couple of years I have worked extensively with #SDWAN. Let me share with you some of the common design mistakes that I see, often to save a few bucks, which ends up costing more in the end. Let's focus on the transports. A 🧵
Don't cheap out on bandwidth. Bandwidth is relatively
cheap. Get two INET transports, from different
providers if possible. Have them be the same BW
and use them equally. Having them different BW
will complicate the design and policy.
2/7
Mar 20, 2022 • 7 tweets • 2 min read
SD-WAN is not so much about providing new tech as it is about making that tech more accessible. Let's take an example of an existing WAN. Possibly a DMVPN or similar.
It's not easy to do traffic engineering with EIGRP and OSPF, especially not with OSPF.
1/x
These are IGPs and were not designed to cater to policy and traffic engineering. With OSPF you basically only have cost to play with. With EIGRP you have bandwidth and delay. However, how do you achieve different view depending on where you are coming from?
2/x
Mar 20, 2022 • 5 tweets • 1 min read
Tell me something about names in your country.
In Sweden surnames like Johansson, Persson, Andersson, Svensson are very common. It literally means Johan's son, Per's son, and so on. There is also Persdotter, Jakobsdotter, which is the same but with daughters. 1/x
There are some men that have a traditionally female name as one of their names. Apparently there are around 25 men with Annika in their name because their heritage is from Annikasgården. 2/x
Feb 26, 2022 • 12 tweets • 3 min read
Reviewing a #CCDE book is definitely taking me back to the days of preparing for and taking the practical. Here are some of the things that can help you perform your best. A 🧵
Connect with the scenario. This may seem obvious but you can't approach this without putting you in the shoes of the network designer. In most exams, you answer a question in isolation. Here, you go along a story and have to live with your decision, and the business as well.
Sep 12, 2021 • 12 tweets • 5 min read
It can be difficult getting the experience to become a network architect, but there are many things you can do even if your role today does not involve design. In this thread I will give you some pointers and feel free to add your own.
1/x
The first step is always the fundamentals. You need to have a good level of understanding of the fundamentals. If you don't know OSPF or ISIS, how will you know when to pick one over the other? You have to start with the fundamentals and get some operational experience also. 2/x
Sep 1, 2020 • 7 tweets • 2 min read
Some thoughts on CL outage, sorry @ioshints too lazy to blog this right now 🙂
First problem was input validation. It shouldn't have been possible to enter wildcards, but the validation failed (buggy code). It would make sense to add more logic here... 1/x
It shouldn't be allowed to filter traffic belong to CL infra, BGP, ISIS, loopbacks, management etc etc...
Second problem was this was implemented without running tests (from what I can tell). The rule could have been tested on a virtual device first. CP is easy to simulate. 2/x
May 3, 2020 • 13 tweets • 3 min read
I've been working for the same company, Conscia, for more than five years now. This thread will describe why I have stayed and will help managers and leaders to understand how you can keep high performers around.
This is going to take a number of tweets.
Everything starts with culture. You can't fake culture. Forget about ping pong tables, free lunch and things of that nature. Those are fine but they are NOT culture. I don't, and probably most other high performers, have zero fucks to give about things like that.
