July 8, 2010

Dynamic Multipoint VPN - DMVPN

One of the most interesting feature of DMVPN as far as my personal opinion goes is its extended support for VRF on MPLS networks. Remember, VRF allows multiple instance of routing tables to co-exist on the same router at the same time. Having said that, DMVPN helps scalling out tradional IPSEC hub-and-spoke VPN configuration by setting permanent and temporary connections, respectively from the spoke routers to the hub router and between the spoker routers as needed. ... Read more

October 18, 2009

MPLS made easy - part 1

MPLS - Multiprotocol Label Switching The only purpose of this post is to demystify MPLS and hopefully give you a solid ground on which to build more knowledge on MPLS. So what is MPLS? Simply said, MPLS is just a forwarding/routing mechanism as opposed to traditional IP routing (static route/BGP/OSPF/RIP etc…) which enables faster IP processing/forwarding by integrating layer 2 information with layer 3 routing… Having said that, we ought to remember than in traditional IP routing, whenever a router receives a packet, the packet is analyzed (DST field) against its forwarding table to determine the next hop. With MPLS, the packets no longer needs to be examined by the router as they are simply routed by looking at the packet tag and forwarded on a pre-configured Label Switch Path (LPS) Before we go on, let’s define some terminology ... Read more