Tag Archives: vrf

VRF Series Article 5 – Stateful Inter-Vrf connectivity

This is the fifth and final article in a series that focused on Segmenting Layer 3 Networks with VRFs. In the third article, we discussed creating a shared services VRF and using it within the otherwise segmented network. In that … Continue reading

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VRF Series Article 4 – VRF-lite in a DMVPN Network

As we’ve progressed through the Segmenting Layer 3 Networks with VRFs series, we have continued to build out a network that looks more like what we would see within an enterprise environment. This post takes it one step further and … Continue reading

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VRF Series Article 3 – Creating a Shared Services VRF

For those following the VRF Series, we currently have a topology built that consists of a segmented Layer 3 first hop network and remotely networked by carrying the isolation from the BrWan router to Main. This article covers, shared services, … Continue reading

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VRF Series Article 2 – Extending L3 Segmentation with VRF-lite

In the last article, we took an initial look at L3 segmentation with VRFs. In that case, we created a basic first hop configuration that had isolated pci and data segments. In reality, most networks are far larger and more … Continue reading

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VRF Series Article 1 – Basic L3 Segmentation with VRFs

Network engineers are well aware of the Layer 2 isolation properties of VLANs. Their use is so pervasive that they are second nature to most. This article is the first in a series that outlines specifically how VRFs can be … Continue reading

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Segmenting Layer 3 Networks with VRFs

I am creating a multi-part series that focuses on Layer 3 network segmentation. This post serves as a landing point and aggregation place for these topics. As the series is built out, the individual links will be available below. Articles … Continue reading

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Voice Gateway and Voice VRF – Caveats

Many networks leverage what is known as a VRF. These are used for traffic isolation and create separate routing instances within a router. It is important that vrf awareness is confirmed for any service (DHCP, Voice GW, etc) being locally … Continue reading

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Combining GRE and IPSec with a Front Side VRF

The article last week focused on the process of taking a typical GRE configuration and reconfiguring it so the transport network was in a separate VRF. This type of VRF is called a FVRF or front-end vrf. While this provides … Continue reading

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VTY access-class Behavior With VRFs

Over the past few weeks, I have posted several introductory articles that deal with the concept of VRFs. One behavior that is modified when VRFs are introduced is the VTY access-class command. A router that is configured for VRFs will … Continue reading

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VRFing 103, Using NAT Virtual Interfaces for Global Reachability

The last few technical articles I’ve written have been around the topic of VRFs. VRF, short for Virtual Routing an Forwarding, is basically a way to carve out areas of isolation in your router. The way this is accomplished is … Continue reading

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VRFing 102, Providing Internet Access With Dynamic PAT

Last week I wrote an article called VRFing 101, Understanding VRF Basics. This was a short and simple introduction into a technology that provides tremendous flexibility for network designers. With flexibility, complexity always follows. This is true in the case … Continue reading

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VRFing 101, Understing VRF Basics

When most engineers think about VRF, they think about MPLS. VRF, short for Virtual Routing and Forwarding, is one of the features that enable designers to create flexible MPLS network designs. However we are going going to completely forget about … Continue reading

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