Podcast
Questions and Answers
What command would be used to ensure the community value appears in the BGP routing table?
What command would be used to ensure the community value appears in the BGP routing table?
What does the community value '64512:600' indicate in the route-map COMM?
What does the community value '64512:600' indicate in the route-map COMM?
In the output of 'show ip bgp 10.10.10.0', what does the term 'localpref 100' imply?
In the output of 'show ip bgp 10.10.10.0', what does the term 'localpref 100' imply?
What could be a reason the community value is not found in the BGP routing table despite being set?
What could be a reason the community value is not found in the BGP routing table despite being set?
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How does the command 'neighbor 10.1.1.1 remote-as 1' affect BGP routing?
How does the command 'neighbor 10.1.1.1 remote-as 1' affect BGP routing?
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R2#show run | begin bgp
router bgp 64512
neighbor 10.1.1.1 remote-as 1
network 10.10.10.0 mask 255.255.255.0 route-map COMM
route-map COMM permit 10
set community 64512:600
R2#show ip bgp 10.10.10. 0
BGP routing table entry for 10.10 10.0/24，version 1320 Paths: (1 available, best #1)
Local 0.0.0.0 from 0.0.0.0 (1.1.1.1)
Origin IGP, metric 0, localpref100, weight 32768,
valid, sourced, local, best
Community 64512:600
Refer to the exhibit. The eBGP neighbor 10.1.1.1 of router R2 receives and installs the prefix,but the community
value is not found in the BGP routing table. How must this issue be resolved?
R2#show run | begin bgp
router bgp 64512 neighbor 10.1.1.1 remote-as 1 network 10.10.10.0 mask 255.255.255.0 route-map COMM
route-map COMM permit 10 set community 64512:600
R2#show ip bgp 10.10.10. 0 BGP routing table entry for 10.10 10.0/24，version 1320 Paths: (1 available, best #1) Local 0.0.0.0 from 0.0.0.0 (1.1.1.1) Origin IGP, metric 0, localpref100, weight 32768, valid, sourced, local, best Community 64512:600 Refer to the exhibit. The eBGP neighbor 10.1.1.1 of router R2 receives and installs the prefix,but the community value is not found in the BGP routing table. How must this issue be resolved?
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Study Notes
BGP Configuration for Router R2
- Router R2 operates under BGP Autonomous System Number (ASN) 64512.
- It configures a neighbor with IP address 10.1.1.1 belonging to ASN 1.
- The command
network 10.10.10.0 mask 255.255.255.0 route-map COMMis used to advertise route 10.10.10.0 with a specified subnet mask and route-map.
Route-Map Configuration
- A route-map named COMM allows traffic and assigns a community value using
set community 64512:600. - This configuration permits matching routes with the highest priority.
BGP Routing Table Entry
- The routing table has an entry for the subnet 10.10.10.0/24 with version number 1320.
- The best path is sourced from local IP 0.0.0.0 with various attributes:
- Origin marked as IGP
- Metric set to 0
- Local preference of 100
- Weight of 32768
- The path is valid, sourced, local, and identified as the best route.
- It is tagged with the community value 64512:600.
Issue with Community Value
- The eBGP neighbor (10.1.1.1) successfully receives and installs the prefix into its table.
- The community value 64512:600, however, is not appearing in the BGP routing table as expected.
Resolution Steps for the Community Value Issue
- Confirm the BGP configurations on both peers to ensure the community values are being recognized and correctly propagated.
- Check local policies or filters that might be excluding certain community values from being accepted or advertised.
- Utilize debug commands to analyze the BGP updates and advertisements to diagnose where the community assignment might be failing.
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Description
This quiz covers the basics of BGP (Border Gateway Protocol) configurations and the analysis of routing tables. It explores neighbor relationships, community settings, and BGP routing entries using specific examples. Test your understanding of BGP concepts and commands.
