This post discusses about design considerations when interconnecting two tightly coupled fabrics using dark fibers or DWDM, but not limited to Metro distances. If we think very long distances, the point-to-point links can be also established using a virtual overlay such as EoMPLS port x-connect; nonetheless the debate will be the same.
Notice that this discussion is not limited to one type of network fabric transport, but any solutions that use multi-pathing is concerned, such as FabricPath, VxLAN or ACI.
Assuming the distance between DC-1 and DC-2 is about 100 km; if the following two design options sound quite simple to guess which one might be the most efficient, actually it’s not as obvious as we could think of, and a bad choice may have a huge impact for some applications. I met several networkers discussing about the best choice between full-mesh and partial-mesh for interconnecting 2 fabrics. Some folks think that full-mesh is the best solution. Actually, albeit it depends on the distances between network fabrics, this is certainly not the most efficient design option for interconnecting them together.
Partial-Mesh with transit leafs design (left) Continue reading
What happens when network engineers with strong programming background and focus on open source tools have to implement network automation in a multi-vendor network? Instead of complaining or ranting about the stupidities of traditional networking vendors and CLI they write an abstraction layer that allows them to treat all their devices in the same way and immediately open-source it.
Read more ...Oracle has a tough quarter with its top line business shrinking quickly as developers choose open source databases instead. – Source: Bloomberg At a business level, there is definitely a trend by corporates to “avoid” Oracle as licensing fees have increased dramatically to reach a pain threshold that CIOs cannot ignore. While the choice for […]
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A strategy overhaul turns Pluribus into an all-software startup.
Presenter: Arkadiy Shapiro, Manager Technical Marketing (Nexus 2000 – 7000) @ArkadiyShapiro
You could say I’m obsessed with BFD –Arkadiy
The focus on this session is around failure detection (not reconergence, protocol tuning, etc). This session will not go over user-driven failure detection methods (ping, traceroutes, etc).
Fast failure detection is the key to fast convergence.
Routing convergence steps:
Failure detection tools: a layered approach: Layer 1, 2, MPLS, 3, application.
Interconnect options:
Think about this: moving to higher speeds (1G -> 10G -> 40G -> beyond) means that more data is lost as you move to higher speeds without changing the failure detection/reconvergence characteristics of the network. 1 second reconvergence time at 1G is way different than 1 second at 40G.
Be aware: ISSU may not support aggressive timers on various protocols. Another reason to be wary of timer cranking.
A Cisco white box is a possibility, John Chambers says.