What is ip fast reroute?
Fast Reroute is a MPLS (Multiprotocol Label Switching) and IP resiliency technology to provide fast traffic recovery upon link or router failures for mission critical services. Upon any single link or node failures, it could be able to recover impacted traffic flows in the level of 50 ms.
Which ones are types of fast reroute?
In this post you will see the following mechanism for fast reroute, pros and cons of each one of them and applications of these mechanisms.
- Loop Free Alternates (RFC5286, deployable today)
- Remote Loop Free Alternates (draft in RTGWG, implemented by some vendors)
- MRT-FRR (draft in RTGWG, proto-types in progress)
How does fast reroute work?
Fast Reroute provides link protection to LSPs. This enables all traffic carried by LSPs that traverse a failed link to be rerouted around the failure. When R2 is notified that the link between it and R3 is no longer available, it simply forwards traffic destined for R3 through the backup tunnel.
What is LFA in OSPF?
OSPF Loop-Free Alternate (LFA) Fast Reroute (FRR) allows OSPF to quickly switch (within 50 ms) to a backup path when a primary path fails. This allows OSPF to run SPF with any other router in the area as the root, finding usable backup paths.
What is MPLS TE FRR?
Traffic engineering (TE) fast reroute (FRR) protects links and nodes on MPLS TE tunnels. If a link or node fails, TE FRR rapidly switches traffic to a backup path, minimizing traffic loss.
What is remote LFA?
This tunneling method to a remote router to use it as an alternate backup path is called remote LFA (Loop-Free Alternate) FRR (Fast Reroute). A targeted MPLS LDP session between the two routers is used for the tunnel. P space: these are the routers that R1 can reach without using the failed link.
What is BGP fast reroute?
When a link fails, the packets on the link are discarded, and a routing loop might occur until BGP completes routing convergence based on the new network topology. You can enable BGP fast reroute (FRR) to resolve this issue. When the link to Router D fails, BGP directs packets to the backup next hop.
What is L BGP?
Border Gateway Protocol (BGP) is the routing protocol for the Internet. Much like the post office processing mail, BGP picks the most efficient routes for delivering Internet traffic.
What is BGP pic?
PIC (Prefix Independent Convergence) is a feature to decrease the data plane convergence time. There are two flavors: BGP PIC Core: decreases convergence time when a core router fails and your IGP has to find a new best path to your PE router.
What is RLFA?
Remote LFA (RLFA): The use of a PQ node rather than a neighbor of the repairing node as the next hop in an LFA repair [RFC5286].
How can I reduce BGP convergence time?
Optimizing BGP and IGP interaction requires the following: Tuning the underlying IGP for fast convergence. It is possible to tune the IGP even for large network to converge under one second. Enabling BGP Next-Hop Tracking process for all BGP speakers and tuning the BGP NHT delay in accordance with IGP response time.
What is FRR routing?
Free Range Routing or FRRouting or FRR is a network routing software suite running on Unix-like platforms, particularly Linux, Solaris, OpenBSD, FreeBSD and NetBSD. It was created as a fork from Quagga. FRRouting is distributed under the terms of the GNU General Public License v2 (GPL2).