Sp - Tag - Fryguy's Bloghttps://hugo.fryguy.net/tags/sp/Sp - Tag - Fryguy's BlogHugo -- gohugo.ioenWed, 28 Aug 2013 12:15:34 +0000VASI – VRF Aware Service Infrastructure Interfaces and Global Route Leakinghttps://hugo.fryguy.net/2013/08/28/vasi-vrf-aware-service-infrastructure-interfaces-and-global-route-leaking/Wed, 28 Aug 2013 12:15:34 +0000Fryguyhttps://hugo.fryguy.net/2013/08/28/vasi-vrf-aware-service-infrastructure-interfaces-and-global-route-leaking/Cisco has defined a VASI interface as: VASI is implemented using virtual interfaces that provide the framework necessary to configure a firewall and NAT between VRF instances. Each interface pair is associated with two different VRF instances. The two virtual interfaces, called vasileft and vasiright, in a pair are logically wired back-to-back and are completely symmetrical. Each interface has an index. The association of the pairing is done automatically based on the two interface indexes such that vasileft automatically gets paired to vasiright. So you could look at a VASI interface as like a back-to-back connection between VRFs –  call it a virtual cable of sort.  You can also see that the traditional use of a VASI interface is to connect two VRFs, on the same router, together so they can route and NAT between each other.  But what I am saying about Global Route Leaking? Well, recently I had a problem where a client wanted to leak routes, dynamically, from a VRF to the Global table on an ASR1000 with an RP1 installed.  We could easily have done it via a physical cable, but I knew their had to be a better way.  I did some digging on the VASI interface and possible configurations and came across this –  added in IOS XE 3.10S code is the ability to actually BGP peer over the VASI interfaces to exchange routes.
You may click on the image below to view the PDF on this.]]>Basic MPLS with VRF, RD, and BGP VPNv4https://hugo.fryguy.net/2011/09/09/basic-mpls-with-vrf-rd-and-bgp-vpnv4/Fri, 09 Sep 2011 18:20:54 +0000Fryguyhttps://hugo.fryguy.net/2011/09/09/basic-mpls-with-vrf-rd-and-bgp-vpnv4/

Since I am starting out my SP studies again I figured I would do a post on basic MPLS VPNs with VRFs and just use static routes. These are some of the base fundamentals in a MPLS VPN deployment, and from here you can quickly build out and add complexities if you wish. What I will cover here is VRF, RD, LDP, and MP BGP configurations and I will start by defining and explaining the technologies.
Virtual Routing and Forwarding, or VRF for short, is a technology that allows a router to have multiple instances of a routing table at the same time. These routing tables co-exist on the router, but yet are segmented and independent of each other. An analogy would be Server virtualization. You can have a single server running VMWare, and then under that have multiple instances of Windows running independently of each other. You can configure those servers to talk to each other, or completely isolate them away and they will have no knowledge of each other.
A Route Distinguisher, or RD, is a way to identify a VPN route in an MPLS network. What this does is add an 8-byte value to an IPv4 prefix to create a VPNv4 prefix, typically referred to as an VPN-IPv4 address. Since each customer is assinged a unique RD, their addresses are guaranteed to be unique. So if you have Customer A that has a 10/8 address space and Customer B that also has a 10/8 address space, the addition of the RD brings uniqueness to each of them. A RD looks nomally looks like 1:100

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