Introduction Flex link is a Cisco solution which replaces STP in certain network topologies. It works by detecting link down on a primary interface and then bringing up the backup interface that has been defined as backup. It is most
Resilient Ethernet Protocol (REP)
Introduction I’m writing a short summary of REP as part of my CCDE studies. REP is an alternative protocol used in place of STP and is most often run in ring based topologies. It is not limited to these topologies
Sign up for ipSpace webinars and get a 20% discount
I posted about ipSpace webinars a couple of days ago and Ivan has kindly agreed to provide a 20% discount for the readers of this blog. Follow this link to sign up for the yearly subscription at a 20% discount.
IPSPACE Webinars with Ivan Pepelnjak
Introduction Want to learn more about data center networks? How do you scale a data center? How do you deploy IPv6 in the real world? What are overlays and which protocols can be used to create overlays? If these kind
Cisco VIRL – Let’s go viral!
Cisco VIRL Most of you have probably heard something about VIRL already. There were some rumors going around and then at Cisco Live, Joel Obstfeld from Cisco did a demo of Cisco VIRL. VIRL is a tool running on Openstack
One year as a CCIE
One year ago today I passed the lab in Brussels! Time flies. That means I have one year to recert. My plan is to use the DE written to recert. Good luck to anyone pursuing the CCIE!
Network Campus Design
Introduction Modern networks need to be enabled for voice and video. These applications do not tolerate a lot of loss before quality becomes unacceptable. This requires us to build networks that are scalable, resilient and converge quickly. This post will
Detecting Network Failure
Introduction In todays networks, reliability is critical. Reliability needs to be high and convergence needs to be fast. There are several ways of detecting network failure but not all of them scale. This post takes a look at different methods
Scaling PEs in MPLS VPN – Route Target Constraint (RTC)
Introduction In any decent sized service provider or even an enterprise network running MPLS VPN, it will most likely be using Route Reflectors (RR). As described in a previous post iBGP fully meshed does not really scale. By default all
iBGP – Fully meshed vs Route Reflection
Intro This post looks at the pros and cons with BGP Route Reflection compared to running an iBGP full mesh. Full mesh Because iBGP routes are not propagated to iBGP sessions there must be a full mesh inside the BGP