ldp

LDP and RSVP-TE are both signaling protocols used for establishing LSP in the MPLS networks. The latter one provides traffic engineering capability and in this article, I will try to set basic MPLS-TE tunnels on IOS XR devices to show you a problem, you can run into. A label switched path (LSP) is a sequence of LSR that switch a labeled packet through an MPLS network. As long LSP is contiguous (end-to-end between PE routers) there should be no problem in forwarding packets. Typically in the service provider core network, LDP will be enabled and RSVP-TE will run on top of it, but in this scenario, LDP is not enabled. ...

The Label Distribution Protocol (LDP) allocates a local label for every route learned from the IGP. But the question is, do we really need a label for every route? The short answer is no! We can optimize LDP and save resources by allocating labels only to the Provider Edge (PE) routers. Let’s test in the lab on IOS and IOS XR devices. Diagram Every router has a Loopback0 configured with IP address X.X.X.X/32, where X is the router number, i.e R2 (2.2.2.2/32) Transit links are configured with IP addresses 10.X.Y.0/24, where X and Y are adjacent router numbers, i.e. the link between R1 and R2 is 10.1.2.0/24 R1-R4, R6, R7 are IOS devices and R5 is running IOS XRv In SP 65000 network IS-IS is configured as IGP with MPLS enabled on every core link Configuration R1-PE ...