Cisco NCS 5500 Series Configuration Manual page 22

Tune BGP Best-Path Calculation
SUMMARY STEPS
1. configure
2. router bgp as-number
3. bgp bestpath med missing-as-worst
4. bgp bestpath med always
5. bgp bestpath med confed
6. bgp bestpath as-path ignore
7. bgp bestpath compare-routerid
8. commit
DETAILED STEPS
Step 1
configure
Step 2
router bgp as-number
Example:
RP/0/RP0/CPU0:router(config)# router bgp 126
Specifies the autonomous system number and enters the BGP configuration mode, allowing you to configure the BGP
routing process.
Step 3 bgp bestpath med missing-as-worst
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp bestpath med missing-as-worst
Directs the BGP software to consider a missing MED attribute in a path as having a value of infinity, making this path
the least desirable path.
Step 4
bgp bestpath med always
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp bestpath med always
Configures the BGP speaker in the specified autonomous system to compare MEDs among all the paths for the prefix,
regardless of the autonomous system from which the paths are received.
Step 5 bgp bestpath med confed
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp bestpath med confed
Enables BGP software to compare MED values for paths learned from confederation peers.
Step 6 bgp bestpath as-path ignore
Example:
RP/0/RP0/CPU0:router(config-bgp)# bgp bestpath as-path ignore
BGP Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.2.x
12
Implementing BGP