Five Functional Facts About OSPF
It’s funny, in my exerperience, OSPF is the most widely used interior gateway protocol because it “just works” and it’s an IETF standard which means it interops between different vendors and platforms. However, if you really start to look at how OSPF works, you realize it’s actually a highly complex protocol. So on the one hand you get a protocol that likely works across your whole environment, regardless of vendor/platform, but on the other you’re implementing a lot of complexity in your control plane which may not be intuitive to troubleshoot.
This post isn’t a judgement about OSPF or link-state protocols in general. Instead it will detail five functional aspects of OSPF in order to reveal–at least in part–how this protocol works, and indirectly, some of the complexity lying under the hood.
1. OSPF Has Its Own Best Path Decision Process
Ever looked closely at OSPF routes in the show ip route output? You’ll notice flags such as O or O IA beside the route.
O 10.1.14.0 255.255.255.0
[110/21] via 123.1.0.18, 00:00:07, Ethernet0/0
O IA 11.11.11.0 [110/20] via 123.1.0.18, 00:00:07, Ethernet0/0
O IA 123.1. Continue readingMEF, TM Forum, and Service Providers to Standardize LSO APIs
The goal is to be able to orchestrate services across multiple networks.
Into the Gray Zone: Considering Active Defense
Most engineers focus on purely technical mechanisms for defending against various kinds of cyber attacks, including “the old magic bullet,” the firewall. The game of cannons and walls is over, however, and the cannons have won; those who depend on walls are in for a shocking future. What is the proper response, then? What defenses are there The reality is that just like in physical warfare, the defenses will take some time to develop and articulate.
One very promising line of thinking is that of active defense. While the concept is often attributed to some recent action, active defense has been one form of warfare for many centuries; there are instances of what might be called active defense outlined in the Bible and in Greek histories. But it is only recently, in light of the many wars around Israel, that defense in depth has taken on its modern shape in active defense. What about active defense is so interesting from a network security perspective? It is primarily this: in active defense, the defender seeks to tire an attacker out by remaining mobile, misdirecting the attacker, and using every opportunity to learn about the attacker’s techniques, aims, and resources to reflect Continue reading