Juniper: Constrained Shortest Path First (CSPF)

It's time to recap a few basics of MPLS, and in particular of CSPF. The Constrained Shortest Path First (CSPF) algorithm allow an ingress LSR to compute a Label Switched Path (LSP) out of a Traffic Engineering (TE) database, the latter includes various constraints or requirements on how a LSP must be signaled. As you may wonder, CSPF is widely use for traffic engineering purpose, but it's also a prerequisite for two protection mechanisms, namely Fast Reroute (FRR) and link/node protection. In fact, these two, uses the TE database to compute and later signal backup tunnels (or bypass LSPs). CSPF is therefore an important piece on the MPLS chessboard.

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Blog: Minor Updates and IPv6 Support

Today, I come up with a few updates regarding this blog. First, all the contents is now licensed under the terms of a Creative Commons 3.0 License. Second, this website is now available over IPv6.

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Juniper: CoS Schedulers

Schedulers is certainly one of the most important component of Quality of Service (QoS) on Juniper Junos. Schedulers defines the queue parameters your traffic will be subject to. Each queues can receives different scheduling parameters thus allowing for service differentiation.

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OpenStack: First Impressions

This week was mostly dedicated to deploy a two-nodes OpenStack testing environment. I wanted to evaluate this famous cloud platform so many people are talking about. My first impressions were quite positive, unfortunately I am relatively disappointed with the network part of the IaaS platform due to a large number of open issues.

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Juniper: VPLS Multihoming - Multiple PE

There's actually a few ways to avoid bridging loops in a VPLS network. Bridging in a VPLS environment is not really different from a standard Ethernet network, a spanning-tree protocol like the original IEEE 802.1D or any of its variants like RSTP or MSTP can be enabled to block the redundant link(s). Ethernet Ring Protection (ERP) could also be enabled on platforms supporting it (e,g. Juniper MX series), but certainly the most common and effective way is to carefully provision the VPLS VPN instances using BGP and to respect a few basic rules.

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