JN0-102 · Question #319
Given the routing entries shown in the exhibit, which next-hop IP address will be used for the destination IP address 192.168.1.159? (Assume that only static routes are available for the…
The correct answer is D. 10.20.106.10. To determine the next-hop for a destination IP address, a router performs a longest prefix match against its routing table. The destination IP 192.168.1.159 falls within the 192.168.1.128/27 route, which is the most specific match among the available static routes.
Question
Given the routing entries shown in the exhibit, which next-hop IP address will be used for the destination IP address 192.168.1.159? (Assume that only static routes are available for the destination.) user@router> show route protocol static inet.0: 12 destinations, 12 routes (12 active, 0 holddown, 0 hidden) + = Active Route, - = Last Active, * = Both 192.168.1.128/27 *[Static/5] 00:03:13 > to 10.20.106.10 via fe-0/0/5.106 192.168.1.144/29 *[Static/5] 00:03:13 > to 10.20.14.131 via ge-0/0/0.0 192.168.1.192/27 *[Static/5] 00:03:13 > to 10.18.1.1 via ge-0/0/1.0 192.168.1.128/28 *[Static/5] 00:01:06 > to 10.20.14.130 via ge-0/0/0.0
Options
- A10.20.14.130
- B10.18.1.1
- C10.20.14.131
- D10.20.106.10
How the community answered
(26 responses)- A4% (1)
- B4% (1)
- D92% (24)
Why each option
To determine the next-hop for a destination IP address, a router performs a longest prefix match against its routing table. The destination IP 192.168.1.159 falls within the 192.168.1.128/27 route, which is the most specific match among the available static routes.
The route 192.168.1.128/28 (range 192.168.1.128 - 192.168.1.143) does not include the destination 192.168.1.159.
The route 192.168.1.192/27 (range 192.168.1.192 - 192.168.1.223) does not include the destination 192.168.1.159.
The route 192.168.1.144/29 (range 192.168.1.144 - 192.168.1.151) does not include the destination 192.168.1.159.
The IP address 192.168.1.159 falls within the network range of 192.168.1.128/27 (192.168.1.128 - 192.168.1.159). This is the only route that encompasses the destination IP address among the provided options, and it is the longest prefix match compared to any hypothetical less specific route. Therefore, the next-hop associated with this route, 10.20.106.10, will be used.
Concept tested: Longest prefix match routing decision
Source: https://www.juniper.net/documentation/us/en/software/junos/routing-basics/topics/topic-map/routing-protocols-overview.html
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