Prerequisites: CCNP level skills.
Note!
Configuration from Lab 140.
Topology
Task 1
The BGP policy stipulates that the R5's timer to send BGP advertisements should be set to 10 seconds (default: iBGP=5 seconds, eBGP=30 seconds). Also BGP peer loss should be detected in 15 seconds (default=180 seconds). Also improve the BGP scanner operation by decreasing the default value of 60 seconds to 20 seconds.
Solution
Task 1
The BGP policy stipulates that the R5's timer to send BGP advertisements should be set to 10 seconds (default: iBGP=5 seconds, eBGP=30 seconds). Also BGP peer loss should be detected in 15 seconds (default=180 seconds). Also improve the BGP scanner operation by decreasing the default value of 60 seconds to 20 seconds.
R5 Configuration:
!
router bgp 50
no synchronization
bgp router-id 172.16.105.5
bgp log-neighbor-changes
bgp scan-time 20
network 172.16.105.0 mask 255.255.255.0
timers bgp 5 15
neighbor 10.1.35.3 remote-as 100
neighbor 10.1.35.3 advertisement-interval 10
no auto-summary
no synchronization
bgp router-id 172.16.105.5
bgp log-neighbor-changes
bgp scan-time 20
network 172.16.105.0 mask 255.255.255.0
timers bgp 5 15
neighbor 10.1.35.3 remote-as 100
neighbor 10.1.35.3 advertisement-interval 10
no auto-summary
!
Note!
Hello timer is set to 5 seconds following the rule 3 x keepalive = holdtime.
BGP Processes:
- BGP Open - responsible for BGP session establishment.
- BGP I/O - handles queuing and processing updates and keepalive packets.
- BGP Scanner - responsible for conditional route advertisements, route dampening, import and export of routes into VRF (MPLS), and confirms the reachability to the NEXT_HOP (the last one is handled now by BGP next-hop tracking).
- BGP Router - calculates the best path, establishes peers, sends and receives routes and interacts with RIB.
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00809d16f0.shtml#understandbgp
