Which IP address becomes the active next hop for 192.168.102 0/24 when 192.168.101.2 fails?

Refer to the exhibit.

Which IP address becomes the active next hop for 192.168.102 0/24 when 192.168.101.2 fails?
A . 192.168.101.18
B . 192.168.101.6
C . 192.168.101.10
D . 192.168.101.14

View Answer

Answer: A

Explanation:

The ‘>’ shown in the output above indicates that the path with a next hop of 192.168.101.2 is the current best path.

Path Selection Attributes:Weight > Local Preference > Originate > AS Path > Origin > MED > External > IGP Cost > eBGP Peering > Router ID

BGP prefers the path with highest weight but the weights here are all 0 (which indicate all routes that are not originated by the local router) so we need to check the Local Preference. Answer ‘192.168.101.18’ path without LOCAL_PREF (LocPrf column) means it has the default value of 100. Therefore we can find the two next best paths with the next hop of 192.168.101.18 and 192.168.101.10.

We have to move to the next path selection attribute: Originate. BGP prefers the path that the

local router originated (which is indicated with the “next hop 0.0.0.0”). But none of the two best paths is self-originated.

The AS Path of the next hop 192.168.101.18 is shorter than the AS Path of the next hop 192.168.101.10 then the next hop 192.168.101.18 will be chosen as the next best path.