In the last blog post in the VLANs and VRFs in netlab series, I described how we can combine VLANs and VRFs and create a VRF Lite solution with stretched VLANs. Wonder how hard would it be to create a routed multi-hop VRF Lite topology? It’s trivial.
Routed VRF Lite lab topology
Andrea Dainese released an interesting tool that performs automated network discovery, pushes the discovered data into NetBox, and then uses netbox-topology-views plugin to create network topology diagrams.
Definitely worth exploring!
Andrea Dainese released an interesting tool that performs automated network discovery, pushes the discovered data into NetBox, and then uses netbox-topology-views plugin to create network topology diagrams.
Definitely worth exploring!
A recent blog post by Andrew Lerner asks whether Cisco ACI is dead. According to Betteridge’s law of headlines, the answer is NO (which is also Andrew’s conclusion), but I liked this gem:
However, Gartner assesses that Nexus Dashboard Fabric Controller is the optimal fabric management software for most Cisco data center environments.
An automation intent-based system provisioning a traditional routed network is considered a better solution than a black-box proprietary software-defined blob of complexity? Who would have thought…
A recent blog post by Andrew Lerner asks whether Cisco ACI is dead. According to Betteridge’s law of headlines, the answer is NO (which is also Andrew’s conclusion), but I liked this gem:
However, Gartner assesses that Nexus Dashboard Fabric Controller is the optimal fabric management software for most Cisco data center environments.
An automation intent-based system provisioning a traditional routed network is considered a better solution than a black-box proprietary software-defined blob of complexity? Who would have thought…
After discussing rogue IPv6 RA challenges and the million ways one can circumvent IPv6 RA guard with IPv6 extension headers, Christopher Werny focused on practical aspects of this thorny topic: how can we test IPv6 RA Guard implementations and how good are they?
After discussing rogue IPv6 RA challenges and the million ways one can circumvent IPv6 RA guard with IPv6 extension headers, Christopher Werny focused on practical aspects of this thorny topic: how can we test IPv6 RA Guard implementations and how good are they?
Long long time ago, Daniel Dib started an interesting Twitter discussion with this seemingly simple question:
How does a switch/router know from the bits it has received which layer each bit belongs to? Assume a switch received 01010101, how would it know which bits belong to the data link layer, which to the network layer and so on.
As is often the case, Peter Paluch provided an excellent answer in a Twitter thread, and allowed me to save it for posterity.
Long long time ago, Daniel Dib started an interesting Twitter discussion with this seemingly simple question:
How does a switch/router know from the bits it has received which layer each bit belongs to? Assume a switch received 01010101, how would it know which bits belong to the data link layer, which to the network layer and so on.
As is often the case, Peter Paluch provided an excellent answer in a Twitter thread, and allowed me to save it for posterity.
Network terminology was easy in the 1980s: bridges forwarded frames between Ethernet segments based on MAC addresses, and routers forwarded network layer packets between network segments. That nirvana couldn’t last long; eventually, a big-enough customer told Cisco: “I don’t want to buy another box if I already have your too-expensive router. I want your router to be a bridge.”
Turning a router into a bridge is easier than going the other way round1: add MAC table and dynamic MAC learning, and spend an evening implementing STP.
Network terminology was easy in the 1980s: bridges forwarded frames between Ethernet segments based on MAC addresses, and routers forwarded network layer packets between network segments. That nirvana couldn’t last long; eventually, a big-enough customer told Cisco: “I don’t want to buy another box if I already have your too-expensive router. I want your router to be a bridge.”
Turning a router into a bridge is easier than going the other way round1: add MAC table and dynamic MAC learning, and spend an evening implementing STP.
A few weeks ago, Daniel Dib tweeted a slide from Radia Perlman’s presentation in which she claimed IPv6 was the worst decision ever as we could have adopted CLNP in 1992. I had similar thoughts on the topic a few years ago, and over tons of discussions, blog posts, and creating the How Networks Really Work webinar slowly realized it wouldn’t have mattered.
A few weeks ago, Daniel Dib tweeted a slide from Radia Perlman’s presentation in which she claimed IPv6 was the worst decision ever as we could have adopted CLNP in 1992. I had similar thoughts on the topic a few years ago, and over tons of discussions, blog posts, and creating the How Networks Really Work webinar slowly realized it wouldn’t have mattered.
netlab release 1.3 contains two major additions:
Here are some of the other goodies included in this release:
netlab release 1.3 contains two major additions:
Here are some of the other goodies included in this release:
Etienne-Victor Depasquale, a researcher at University of Malta, is trying to figure out what technologies service providers use to build real-life metro-area networks, and what services they offer on top of that infrastructure.
If you happen to be involved with a metro area network, he’d love to hear from you – please fill in this survey – and he promised that he’ll share the results of the survey with the participants.
Etienne-Victor Depasquale, a researcher at University of Malta, is trying to figure out what technologies service providers use to build real-life metro-area networks, and what services they offer on top of that infrastructure.
If you happen to be involved with a metro area network, he’d love to hear from you – please fill in this survey – and he promised that he’ll share the results of the survey with the participants.
It’s so refreshing to find someone who understands the impact of latency on application performance, and develops a methodology that considers latency when migrating a workload into a public cloud: Adding latency: one step, two step, oops by Lawrence Jones.
It’s so refreshing to find someone who understands the impact of latency on application performance, and develops a methodology that considers latency when migrating a workload into a public cloud: Adding latency: one step, two step, oops by Lawrence Jones.
After completing the discussion of basic Kubernetes networking with a typical inter-pod traffic scenario, Stuart Charlton tackled another confusing topic: an overview of what Kubernetes services are.