Preserving Redirect Nexthop - Cisco NCS 6000 Series Configuration Manual

Preserving Redirect Nexthop

Command or Action
42
Extended community: FLOWSPEC
Traffic-rate:100,0
Step 5 show pbr-pal ipolicy all locationnode-id
Preserving Redirect Nexthop
You can explicitly configure redirect nexthop as part of the route specification. Redirect nexthop is encoded
as the MP_REACH nexthop in the BGP flowspec NLRI along with the associated extended community.
Recipient of such a flowspec route redirects traffic as per FIB lookup for the redirect nexthop, the nexthop
can possibly resolve over IP or MPLS tunnel. As the MP_REACH nexthop can be overwritten at a eBGP
boundary, for cases where the nexthop connectivity spans multiple AS's, the nexthop can be preserved through
the use of the unchanged knob.
SUMMARY STEPS
1. configure
2. router bgp as-number
3. neighbor ip-address
4. address-family { ipv4 }
5. flowspec next-hop unchanged
DETAILED STEPS
Command or Action
Step 1 configure
Step 2 router bgp as-number
Example:
RP/0/RP0/CPU0:router(config)# router bgp 100
Step 3
neighbor ip-address
Example:
RP/0/RP0/CPU0:router(config)# router bgp 100
neighbor 1.1.1.1
Step 4
address-family { ipv4 }
Example:
RP/0/RP0/CPU0:router(config-bgp)# router bgp 100
neighbor 1.1.1.1 address-family ipv4
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
120
Purpose
On platform dependent devices, use this command to verify
if a flowspec rule configured on the controller router is
available on the BGP side.
Purpose
Specifies the autonomous system number and enters the
BGP configuration mode, allowing you to configure the
BGP routing process.
Places the router in neighbor configuration mode for BGP
routing and configures the neighbor IP address as a BGP
peer.
Specifies the IPv4 address family and enters address family
configuration submode, and initializes the global address
family.
Implementing BGP Flowspec