fast-reroute tie-break
Use this command to set the tie-breaking policy for selecting a fast reroute repair path. You assign a priority to each type of repair path. The tie-breaker value is used to select an LFA FRR route when multiple LFA FRR routes are available for the same primary route.
Use the no form of this command to set the tie-break preference value for a protection type to its default value.
To set all types of repair paths to their default priorities, do not specify a repair path with the no form of this command.
Command Syntax
fast-reroute tie-break (level-1|level-2) proto (ipv4) (primary-path|interface- disjoint|node-protecting|broadcast-interface-disjoint|secondary-path|downstream- path) index <1-255>
no fast-reroute tie-break (level-1|level-2) proto (ipv4) (primary- path|interface-disjoint|node-protecting|broadcast-interface-disjoint|secondary- path|downstream-path)
Parameters
level-1
Level 1 only.
level-2
Level 2 only.
ipv4
IPv4 address family only.
primary-path
Use a path from the Equal-Cost Multipath Path (ECMP) set. An ECMP found during the primary shortest path first (SPF) repair might not be desirable in networks where traffic exceeds the capacity of any single link.
interface-disjoint
Link protecting: prefer a backup path that uses a different interface than the interface used to reach destination via the primary path.
node-protecting
Bypass the primary-path gateway router which might not protect the router that is the next hop in the primary path. This ensures complete traffic protection even if the primary next-hop router fails.
broadcast-interface-disjoint
Do not use the interface if connected to a broadcast network. Repair paths protect links when a repair path and a protected primary path use different next-hop interfaces. However, on broadcast interfaces, if the repair path is computed via the same interface as the primary path, but their next-hop gateways are different, the router is protected but the link might not be.
secondary-path
Prefer a non-ECMP backup path.
downstream-path
Prefer a backup path to the destination which satisfies the downstream condition where the path cost to reach the destination from the LFA next hop is less than the path cost to the destination from the self node via primary next hop:
Distance_opt(N, D) < Distance_opt(S, D)
This might result in lost traffic, but prevents looping.
index
Tie breaking index. A lower value has higher preference.
<1-255>
Tie breaking index value.
Defaults
primary-path | 20 |
interface-disjoint | 60 |
node-protecting | 30 |
broadcast-interface-disjoint | 70 |
secondary-path | 255 |
downstream-path | 90 |
Command Mode
Router mode
Applicability
This command was introduced before OcNOS-OTN version 4.2.
Examples
#configure terminal
(config)#router isis 100
(config-router)#fast-reroute tie-break level-2 proto ipv4 node-protecting index 127
(config-router)#no fast-reroute tie-break level-1 proto ipv4 broadcastinterface-disjoint
Last modified date: 08/28/2023