Category Archives: Design

Discussion about technology, network, and security design. Includes understanding what something is and how it fits into an overall solution.

MPLS Intro Series – Customer Connection with BGP

In the last article, we performed a packet walk of a simple VPNv4 network. This article will expand our deployment by allowing the CE_Sites to advertise their own routes via BGP. For this configuration, we will use some overlapping and … Continue reading

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When Firepower Management Center Goes Offline

A typical Firepower deployment consists of a management component and a managed device. The management component is known as Firepower Management Center (FMC). The managed device is the NGIPS or NGFW itself and would be leveraging the Firepower or the … Continue reading

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Where to Use a VRF

Very early in our careers, we learn about physical and logical network segmentation. Generally speaking, that understanding comes in the form represented by the diagrams below. Depending on the work environment of an individual, it may take some time before … Continue reading

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Packet Size, It Matters

As I mentioned in a previous post, I have been studying the materials for the Cisco CCDE. One thing that has come up only a time or two is that of MTU. MTU, or maximum transmission unit, is the maximum … Continue reading

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Routing Loop, Failure by Design

I have spent some time studying the CCDE materials. One broken design example that has come up involves route reflector clients that don’t align with the physical topology. This article examines that example and some solutions to the problem. To … Continue reading

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NSSA with Default Route vs Totally NSSA

A question recently came up on CLN about the differences of NSSA with a default route and a Totally NSSA area. The community member was asking if there even was a difference. This is a short example that demonstrates what the … Continue reading

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