The networking industry has recently developed a renewed interest in virtual overlays, often wrapped in an “SDN as the controller” context. Amidst the promise, the hope and the hype, the following questions present themselves:
- What exactly is an overlay?
- What distinguishes an overlay from a VPN?
- How decoupled can an overlay be from the underlay network and what are the tradeoffs?
- What are the advantages of overlays and will they emerge as the new networking world order? Read More »
Tags: E-VPN, LISP, Overlay, TRILL, VXLAN
I’m not a car person and I don’t worry too much about what’s under the hood. That means that I’m just a car user, I only want to turn the ignition key and drive. In the Data Center world, the server team is typically a user of the network. Server guys don’t want to know how the network is implemented. They just want their VLANs to extend to the whole network so that they can connect their devices with no constraint, without having to worry about high availability, risk containment, link provisioning… network stuff. That’s precisely what FabricPath is designed to offer them: a network that looks like a single switch, the simplest networking entity. This “Fabric” offers efficient any-to-any connectivity with high bandwidth and low latency, all without having to understand how it works.
Of course, this user perspective is an abstraction. The following Figure 2 represents an example of the physical topology of the network, a Clos fabric, typical in Data Center environments. Note that this could just as well be a ring, a star, or even a network distributed across two sites. FabricPath turns an arbitrary topology into a Fabric and does not lock you into a particular model.
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Tags: ethernet, Ethernet Fabric, fabric architecture, FabricPath, l2mp, Layer 2, multipathing, nexus, STP, switching, TRILL, Unified Fabric
Here we go again.
I’ve put it off, and put it off, and put it off, because every time I think about writing a piece about FCoE and TRILL I think to myself, “Okay, is this really something that enough people are going to care about to make a difference?” And then one day someone pipes up and brings up TRILL again, and thus the cycle begins anew.
I wonder if it’s related to the new zodiac signs or something.
Because I’m a person who likes to think in visual pictures, I’m going to include some pretty pictures here to help make sure I don’t miss anything along the way. I’ll also try to avoid some of the technical jargon and make it more approachable. Sometimes ya just gotta bring things back to basics. Read More »
Tags: FCoE, FSPF, myths, STP, TRILL