Prerequisites For Ipv4/Ipv6 Loop-Free Alternate Fast Reroute - Cisco NCS 6000 Series Configuration Manual

Implementing IP Fast Reroute Loop-Free
Alternate
IP Fast Reroute Loop-Free Alternate feature enables you to tunnel a packet around a failed link to a remote
loop-free alternate that is more than one hop away.
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Prerequisites for IPv4/IPv6 Loop-Free Alternate Fast Reroute

• Loop-Free Alternate (LFA) Fast Reroute (FRR) can protect paths that are reachable through an interface
• When a LAN interface is physically connected to a single neighbor, you should configure the LAN
Restrictions for Loop-Free Alternate Fast Reroute
• Load balance support is available for FRR-protected prefixes, but the 50 ms cutover time is not guaranteed.
• A maximum of eight FRR-protected interfaces can simultaneously undergo a cutover.
• Only Layer 3 VPN is supported.
• The remote LFA backup path for MPLS traffic can be setup only using LDP.
Prerequisites for IPv4/IPv6 Loop-Free Alternate Fast Reroute, on page 345
Restrictions for Loop-Free Alternate Fast Reroute, on page 345
IS-IS and IP FRR, on page 346
Repair Paths, on page 346
LFA Overview, on page 347
LFA Calculation, on page 347
Interaction Between RIB and Routing Protocols, on page 347
Configuring Fast Reroute Support, on page 348
Configuring IPv4 Loop-Free Alternate Fast Reroute Support: Example, on page 350
Additional References, on page 350
only if the interface is a point-to-point interface.
interface as a point-to-point interface so that it can be protected through LFA FRR.
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
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