Q26Routing Policy and Manipulation
Refer to the exhibit. An engineer has successfully resolved a BGP peering issue. R1 has established eBGP peerings with R2 and R3. Which mechanism should the engineer apply to steer the traffic correctly?
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Community votes
Discussion · 10
5
'A' is wrong because MED won't get compared unless the 'always compare med' knob is enabled.
'B' and 'C' are wrong too.
'D' is the correct answer
4
I would vote for D.
A - could be correct if we configure 'always compare med' on R1 and assume that all prefixes advertised by AS65514 and 65515 have the same AS_PATH length.
B - Local preference on R3 will influence routers in AS6514, not R1 or AS6513.
C - Weight is a router local feature and will not influence Rq
D - Some level of load balancing is achieved by default as BGP prefers the shortest AS_PATH for a certain prefix (Cisco BGP path selection alghortm - rule 4) . If 1-7 rules give no preference for a certain prefix then with rule 8. Prefer lowest IGP metric to BGP next hop we can force traffic to R2 or R3, influencing load distribution.
2
d is correct
1
maybe A is correct??
1
"B" is the correct answer
D 1
Selected Answer: D
D is the correct one
D 1
Selected Answer: D
D by way of process of elimination
1
'A' is the only option that makes sense, assuming that 'always compare med' has to be configured on R1. 'B' and 'C' are obviously wrong, while 'D' would only have made sense if there was another PE in AS 65513 (which is not the case).
A 1
Selected Answer: A
D is incorrect because there is no IGP between R1 , R2 and R3 , so the correct possible answer is A.
A 1
Selected Answer: A
I think A is the closest to being correct. A lot of "guest" and "assume" here.