Flooding Domains versus Areas
At a fundamental level, SPF and IS-IS are similar in operation. They both build neighbor adjacencies. They both use Dijkstra’s shortest path first (SPF) to find the shortest path to every destination in the network. They both advertise the state of each link connected to a network device. There are some differences, of course, such as the naming (OSI addresses versus IP addresses, intermediate systems versus routers). Many of the similarities and differences don’t play too much in the design of a network, though.
One difference that does play into network design, however, is the way in which the two protocols break up a single failure domain into multiple failure domains. In OSPF we have areas, while in IS-IS we have flooding domains. What’s the difference between these two, and how does it effect network design? Let’s use the illustration below as a helpful reference point for the two different solutions.
In the upper network, we have an illustration of how OSPF areas work. Each router at the border of a flooding domain (an Area Border Router, or ABR), has a certain number of interfaces in each area. Another way of saying this is that an OSPF ABR is Continue reading
Flooding Domains versus Areas
At a fundamental level, OSPF and IS-IS are similar in operation. They both build neighbor adjacencies. They both use Dijkstra’s shortest path first (SPF) to find the shortest path to every destination in the network. They both advertise the state of each link connected to a network device. There are some differences, of course, such as the naming (OSI addresses versus IP addresses, intermediate systems versus routers). Many of the similarities and differences don’t play too much in the design of a network, though.
One difference that does play into network design, however, is the way in which the two protocols break up a single failure domain into multiple failure domains. In OSPF we have areas, while in IS-IS we have flooding domains. What’s the difference between these two, and how does it effect network design? Let’s use the illustration below as a helpful reference point for the two different solutions.
In the upper network, we have an illustration of how OSPF areas work. Each router at the border of a flooding domain (an Area Border Router, or ABR), has a certain number of interfaces in each area. Another way of saying this is that an OSPF ABR is Continue reading
Kiev, Ukraine: CloudFlare’s 78th Data Center
Здоровенькі були! CloudFlare just turned up our newest datacenter in Kiev, the capital and largest city of Ukraine.
Kiev is an old city with more than 1,000 years of history. It was the capital of Kievan Rus’, an ancient country which is considered to be the ancestor of modern Ukraine, Belarus and Russia. If you visit the city by plane, you may be almost blinded by the shining golden domes of numerous old churches and cathedrals - and once there, be sure to try the famous Ukrainian beet soup, “Borscht”. CloudFlare decided to contribute to the long history of Kiev with our 22nd data center in Europe, and our 78th data center globally.
Localizing content
Frankfurt is arguably the biggest point of interconnection in the world, and is home to Deutscher Commercial Internet Exchange (DE-CIX) which plays an absolutely critical role and sees close to 5Tbps in traffic. While this is great if you live near Frankfurt, it is also where most traffic is exchanged for other parts of Germany, large parts of Europe (think Austria, Bulgaria, Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Italy, Kazakhstan, Lithuania, Montenegro, Norway, Poland, Romania, Serbia, Turkey, Ukraine, etc.), and even countries such Continue reading
Worth Reading: Declaring IPv6 an Internet Standard
The post Worth Reading: Declaring IPv6 an Internet Standard appeared first on 'net work.
New Poison Ivy Activity Targeting Myanmar, Asian Countries
The infamous Remote Access Trojan (RAT) Poison Ivy (hereafter referred to as PIVY) has resurfaced recently, and exhibits some new behaviors. PIVY has been observed targeting a number of Asian countries for various purposes over the past year. Palo Alto Networks’ Unit 42 recently blogged about a new Poison Ivy variant targeting Hong Kong activists […]DemoFriday with Netronome & Ericsson: Improve Performance & Flexibility of Telco NFV with Intelligent Server Adapters
Achieve up to 5X lower TCO for SDN and NFV applications with hardware-based acceleration of virtual switch processing.
Linux and the Quest for Underlays
I’m at the OpenStack Summit this week and there’s a lot of talk around about building stacks and offering everything needed to get your organization ready for a shift toward service provider models and such. It’s a far cry from the battles over software networking and hardware dominance that I’m so used to seeing in my space. But one thing came to mind that made me think a little harder about architecture and how foundations are important.
Brick By Brick
The foundation for the modern cloud doesn’t live in fancy orchestration software or data modeling. It’s not because a retailer built a self-service system or a search engine giant decided to build a cloud lab. The real reason we have a growing market for cloud providers today is because of Linux. Linux is the underpinning of so much technology today that it’s become nothing short of ubiquitous. Servers are built on it. Mobile operating systems use it. But no one knows that’s what they are using. It’s all just something running under the surface to enable applications to be processed on top.
Linux is the vodka of operating systems. It can run in a stripped down manner on a variety Continue reading