Software-Defined Architecture: What To Consider
As more parts of IT become "software-defined," be sure you're asking the right questions.
Table Sizes in OpenFlow Switches
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Usman asked a few questions in his comment on my blog, including:
At the moment, local RIB gets downloaded to FIB and we get packet forwarding on a router. If we start evaluating too many fields (PBR) and (assume) are able to push these policies to the FIB - what would become of the FIB table size?
Short answer: It would explode ;)
Read more ...General – How to Build a Network Pt.1
Building a strong network of people is very important in creating a successful career in IT. In these posts we will start first look at why building a network is important and in the other posts we will look at how to actually build the network and how to make sure that you are also contributing to the network and not only exploiting it.
If you came here to read about connecting cables or routing protocols, sorry, this is not that kind of post. This post is about how to build a network of people.
People often understimate the power of having a big reach in the industry through a network of people. I often hear in my role that I’m almost too effective sometimes. Part of that is because I have a very good network of people that I trust and rely on. In this blog we will look at WHY you want to build a network of people.
The Borg Mind – Have you heard of Star Trek? No? Are you sure you work in IT? 
Jokes aside, there is species called the Borg in the series which do not so nice things. What it is nice about Continue reading
Ubiquity gear replacing BT HomeHub router
These are my notes from setting up Ubiquity wifi access point and router to replace the horrible BT HomeHub 5.
What’s wrong with BT HomeHub?
- It can’t hand out non-BT DNS servers
(and BT’s DNS servers MITM your queries and spoof NXDOMAIN
if the reply has rfc1918 addresses in them. This is known
and they “can’t” turn this off)
- This means that I had to turn off the DHCP server and run my own on a raspberry pi. So I’m actually replacing two devices. It was already not a all-in-one-box solution.
- The port forwarding database is not using unique key constraints, so you have to try and re-try adding port forwardings until you’re lucky and don’t hit a key collision.
- Only one wifi network. I want untrusted things (IoT) to be firewalled from the rest.
- I want to deny Internet access to some IoT things. I don’t need them to be able to connect anywhere. HomeHub doesn’t support that.
- Wifi range is not great. Not terrible, but bad enough that it doesn’t cover my home.
- I don’t know if it’s to blame, but I did not have a good experience trying to set up a second AP to automatically roam Continue reading
Ubiquity gear replacing BT HomeHub router
These are my notes from setting up Ubiquity wifi access point and router to replace the horrible BT HomeHub 5.
What’s wrong with BT HomeHub?
- It can’t hand out non-BT DNS servers
(and BT’s DNS servers MITM your queries and spoof NXDOMAIN
if the reply has rfc1918 addresses in them. This is known
and they “can’t” turn this off)
- This means that I had to turn off the DHCP server and run my own on a raspberry pi. So I’m actually replacing two devices. It was already not a all-in-one-box solution.
- The port forwarding database is not using unique key constraints, so you have to try and re-try adding port forwardings until you’re lucky and don’t hit a key collision.
- Only one wifi network. I want untrusted things (IoT) to be firewalled from the rest.
- I want to deny Internet access to some IoT things. I don’t need them to be able to connect anywhere. HomeHub doesn’t support that.
- Wifi range is not great. Not terrible, but bad enough that it doesn’t cover my home.
- I don’t know if it’s to blame, but I did not have a good experience trying to set up a second AP to automatically roam Continue reading
Managing Cisco IOS Upgrades with Ansible
I was recently asked to automate the way a client handles Cisco IOS upgrades. As I’ve been using Ansible a lot lately I decided to start there. Basically the steps required to do the upgrade can be broken down into parts which map quite nicely to tasks in an Ansible playbook. Even if you aren’t using IOS you might find it interesting to see how different Ansible modules can be combined in order to complete a set of tasks.
AT&T Considers Open Sourcing Its SDN ‘Foundation’
John Donovan introduces Ecomp on the ONS 2016 stage.
Managing Cisco IOS Upgrades with Ansible
I was recently asked to automate the way a client handles Cisco IOS upgrades. As I’ve been using Ansible a lot lately I decided to start there. Basically the steps required to do the upgrade can be broken down into parts which map quite nicely to tasks in an Ansible playbook. Even if you aren’t using IOS you might find it interesting to see how different Ansible modules can be combined in order to complete a set of tasks.
Continue reading
It’s More than Just IoT Security, it’s Security at Scale
By: Abhi Maras, Cloudpath Product Line Manager According to IDC, the global market for Internet of Things (IoT) is projected to reach $7.1 trillion by 2020, and the number of IoT devices is projected to grow from 13 to 30...ONS Kickoff: Open Source Needs to Stay Open
Open source and networking do mix, but not easily.
Reaction: More Encryption is Bad?
This week I was peacefully reading the March 9th issue of ACM Queue when I received a bit of a surprise. It seems someone actually buys the “blame the victim” game, arguing that governments are going to break all encryption if we don’t give them what they want.
These ideas are all based on the same principle: If we cannot break the crypto for a specific criminal on demand, we will preemptively break it for everybody. And whatever you may feel about politicians, they do have the legitimacy and power to do so. They have the constitutions, legislative powers, courts of law, and police forces to make this happen. The IT and networking communities overlooked a wise saying from soldiers and police officers: “Make sure the other side has an easier way out than destroying you.” But we didn’t, and they are.
If you don’t get the point, it’s simple: the only way to really have secure communications is to give the government the keys. Once again, my inner philosopher threw up (as I recently said on a Network Break podcast). The reason I find the line of argument above so horrifying is simple: it’s just true enough to Continue reading