Led by Brian McGahan, Border Gateway Protocol (BGP) is an important part of the CCIE Enterprise Certification process, now updated for the 2020 exam changes.
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This weekend while working on content updates for CCIE R&S Version 5, I ran into an interesting problem. In order to test some nuances of routing protocol updates and packet fragmentation, I was trying to generate BGP UPDATE messages that would exceed the transit MTU. To do this I manually created a bunch of Loopback interfaces and did a redistribute connected into BGP. When I looked at the packet capture details, I started to realize how many routes I'd actually need in order to fill up the...
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Five hours of new videos have been added to INE's CCIE Service Provider Version 3.0 Advanced Technologies Class which cover Multicast VPN and QoS support for Layer 3 MPLS VPNs. Specifically these videos cover Multicast VPN & QoS theory, configuration, verification, and troubleshooting on both regular IOS and IOS XR, including PIM Sparse Mode, PIM Source Specific Multicast, VRF Aware PIM, Multicast Distribution Trees, BGP MDT exchange, and SP QoS Classification, Marking, Scheduling, and...
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One of our most anticipated products of the year - INE's CCIE Service Provider v3.0 Advanced Technologies Class - is now complete! The videos from class are in the final stages of post production and will be available for streaming and download access later this week. Download access can be purchased here for $299. Streaming access is available for All Access Pass subscribers for as low as $65/month! AAP members can additionally upgrade to the download version for $149.
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The BGP MED attribute, commonly referred to as the BGP metric, provides a means to convey to a neighboring Autonomous System (AS) a preferred entry point into the local AS. BGP MED is a non-transitive optional attribute and thus the receiving AS cannot propagate it across its AS borders. However, the receiving AS may reset the metric value upon receipt, if it so desires. Previous versions of BGP (v2 and v3) defined this attribute as the inter-AS metric (INTER_AS_METRIC) but in BGPv4 it is...
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Abstract This publication briefly covers the use of 3rd party next-hops in OSPF, RIP, EIGRP and BGP routing protocols. Common concepts are introduced and protocol-specific implementations are discussed. Basic understanding of the routing protocol function is required before reading this blog post. Overview Third-party next-hop concept appears only to distance vector protocol, or in the parts of the link-state protocols that exhibit distance-vector behavior. The idea is that a distance-vector...
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One of the common questions that comes up is "Why does the router choose THAT route? We all know, (or at least after reading the list below, we will know), that BGP uses the following order, to determine the "best" path. So now for the question. Take a look at the partial output of the show command below:
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Last week we wrapped up the MPLS bootcamp, and it was a blast! A big shout out to all the students who attended, as well as to many of the INE staff who stopped by (you know who you are :)). Thank you all. Here is the topology we used for the class, as we built the network, step by step. The class was organized and delivered in 30 specific lessons. Here is the "overview" slide from class:
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The purpose of event dampening is reducing the effect of oscillations on routing systems. In general, periodic process that affect the routing system as a whole should have the period no shorter than the system convergence time (relaxation time). Otherwise, the system will never stabilize and will be constantly updating its state. In reality, complex system have multiple periodic processes running at the same time, which results is in harmonic process interference and complex process spectrum....
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