Ensure that the Border Gateway Protocol (BGP) and the IP or Multiprotocol Label Switching (MPLS) network is up and running
at the customer site that is connected to the provider site by more than one path (multihomed).
Ensure that the backup or alternate path has a unique next hop that is not the same as the next hop of the best path.
Enable the Bidirectional Forwarding Detection (BFD) protocol to quickly detect link failures of neighbors that are directly
Restrictions for BGP PIC
Unlabeled BGP PIC EDGE for global prefixes is not supported.
TE, SR, SR-TE, flex-LSP are not supported.
BVI as a core is not supported.
Only one primary and one backup path is supported. No support for multiple primary paths and one backup path.
PIC EDGE is supported for Global IPv4, IPv6 (6PE), and MPLS-VPN prefixes (VPNv4 and VPNv6).
By default, IPv4 global prefixes are installed with primary and backup path (if available) in the hardware. To install the
protection in IPv6 (6 PE), VPNv4, and VPNv6 prefixes in the hardware, you must configure CLI cef encap-sharing disable command in global configuration mode.
This CLI reprograms the CEF completely and impacts traffic. We recommend that you do it in the maintenance window.
RP/0/RP0/CPU0:router(config)# router bgp 100
Specifies the autonomous system number and enters the BGP configuration mode, allowing you to configure the BGP routing process.
Configures extra paths selection mode for a prefix.
Use the additional-paths selection command with an appropriate route-policy to calculate backup paths and to enable Prefix-Independent Convergence (PIC) functionality.
The route-policy configuration is a prerequisite for configuring the additional-paths selection mode for a prefix. This is
an example route-policy configuration to use with additional-selection command:
set path-selection backup 1 install