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QID:NE115 - BGP load balancing influencing other Autonomus Systems - joshuad31 - 03-17-2010
Hello,
After looking at this question I think that perhaps the answer should include the network with the 20% load rather than the 45% load. This is why I feel it should be so:
The neighbor sending the 65% inbound load needs to be brought down by 20% and the neighbor with the 20% load needs to have his load increased by 20%. Right now hosts attempting to reach either network 10.10.1.32 or 10.10.1.48 are preferring the 65% load path through network 192.168.20.x rather than the 20% load path through network 192.168.30.x . We need to tell these hosts that the cost to reach this path is higher over the 65% link than over the 20% link. Your proposed solution would re balance traffic as 65% 20% with the load on the links reversed.
So the answer should include this statement:
access-list 50 permit 10.10.1.32 0.0.0.240
rather than the following statement which you indicate as correct:
access-list 50 permit 10.10.1.16 0.0.0.240
Question with your proposed solution below
23. (QID:NE115) View the exhibit. Currently the two eBGP links between AS100 and AS200 have an average inbound load of 65% and 20% respectively. After further investigation, traffic to 10.10.1.16/28 accounts for 45%, and traffic to 10.10.1.32/28 and to 10.10.1.48/28 each account for 20% of the inbound load. The BGP attributes are currently set at their default values in both autonomous systems.
If you want to influence how AS200 sends traffic to AS100, which eBGP configurations would you configure in AS100 to influence AS200 to use the eBGP links more evenly? (Choose two.)
route-map as_50 permit 10
match ip address 50
set metric 150
access-list 50 permit 10.10.1.16 0.0.0.240
neighbor 192.168.30.2 route-map as_50 out
neighbor 192.168.20.2 route-map as_50 out
route-map as_50 permit 10
match ip address 50
set metric 150
access-list 50 permit 10.10.1.32 0.0.0.240
Correct Answer:
route-map as_50 permit 10
match ip address 50
set metric 150
access-list 50 permit 10.10.1.16 0.0.0.240
neighbor 192.168.20.2 route-map as_50 out
Re: QID:NE115 - BGP load balancing influencing other Autonomus Systems - forumsupport - 04-19-2010
Thank you. The answer has been corrected.