Real Life BGP Route Origination and BGP Next Hop Intricacies

During one of the ExpertExpress engagements I helped a company implement the BGP Everywhere concept, significantly simplifying their routing by replacing unstable route redistribution between BGP and IGP with a single BGP domain running across MPLS/VPN and DMVPN networks.

They had a pretty simple core site network, so we decided to establish an IBGP session between DMVPH hub router and MPLS/VPN CE router (managed by the SP).

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Quantum SDN

An interesting startup is launching their SDN solution @ Interop Las Vegas today: Quantum Networks use the latest quantum computing technology to solve some of the hardest problems of controller-based networking.

One of the fundamental problems of hardware-based OpenFlow solutions is the flow update rate – most switches using merchant silicon can insert around 1000 new flows per second into their forwarding tables. Technologies based on quantum mechanics effects change all that – a quantum entanglement technology patented by Quantum Networks can install new flows instantaneously across the whole network.

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STP in Brocade VCS Fabric – an Interesting Solution after a Long Wait

Update 2021-01-03: The VCS Fabric idea was sent to the graveyard when Brocade Product Management discovered VXLAN and EVPN a few years before they were acquired by Extreme.

A few years ago I lambasted the lack of STP support in Brocade’s VCS fabric. It took Brocade over two years to solve the problem, but they finally came up with an interesting end-to-end solution.

Here are a few highlights; for more details read the Configuring STP-type Protocols section in Network OS Administrator Guide.

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What Happened to “Be Conservative in What You Do”?

A comment by Pieter E. Smit on my vSphere Does Not Need LAG Bandaids post opened yet another can of worms: vSphere behavior on uplink recovery.

Short summary: vSphere starts using an uplink as soon as its physical layer becomes operational, which might happen during ToR switch startup phase, or before a ToR switch port enters forwarding state.

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Scaling BGP-Based DMVPN Networks

Cristiano sent me an interesting question:

I saw that to configure BGP as the routing protocol running over DMVPN I have to configure BGP neighbors on the hub site router. Do I really have to configure all the neighbors on the hub site? How many neighbors could I configure? How can I scale that?

According to Cisco Live presentations, BGP-over-DMVPN scales to several thousand spoke sites (per hub router), so you shouldn’t be too worried about the protocol scalability. Configuring all those neighbors is a different issue.

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