HPE7-A06 · Question #15
Refer to the exhibit. Company XYZ is using AOS-CX on Agg-1 and Agg-2. Both routers already have established eBGP connections as shown in the diagram but XYZ engineers are concerned that they could bec
The correct answer is C. ip aspath-list bgp-local permit ^$ route-map bgp-ebgp-out permit match aspath bgp-local exit. To avoid becoming a transit AS, advertise only prefixes originated locally. Use an AS-path filter that matches an empty path (^$) and permit only those routes in the outbound route-map applied to each eBGP neighbor. This prevents re-advertising routes learned from one ISP to anot
Question
Refer to the exhibit. Company XYZ is using AOS-CX on Agg-1 and Agg-2. Both routers already have established eBGP connections as shown in the diagram but XYZ engineers are concerned that they could become a transit AS for other ISPs. XYZ engineers have proposed the following configuration changes on both Agg-1 and Agg-2:
Which script below will complement the configuration shown while avoiding XYZ becoming a transit AS? A. B. C. D.
Exhibits
Options
- Aip aspath-list bgp-local permit ^64500$ route-map bgp-ebgp-out permit match aspath bgp-local exit
- Bip aspath-list bgp-local permit ^64500$ route-map bgp-ebgp-out deny match aspath bgp-local exit router bgp 64500 address-family ipv4 unicast neighbor <ip of ebgp-neighbor> route-map bgp-ebgp-out both exit
- Cip aspath-list bgp-local permit ^$ route-map bgp-ebgp-out permit match aspath bgp-local exit
- Dip aspath-list bgp-local permit ^$ route-map bgp-ebgp-out deny match aspath bgp-local exit
How the community answered
(37 responses)- A11% (4)
- B27% (10)
- C57% (21)
- D5% (2)
Explanation
To avoid becoming a transit AS, advertise only prefixes originated locally. Use an AS-path filter that matches an empty path (^$) and permit only those routes in the outbound route-map applied to each eBGP neighbor. This prevents re-advertising routes learned from one ISP to another.
Topics
Community Discussion
No community discussion yet for this question.