An enterprise Cisco router displays the following IPv4 routing table output:
text
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 4 subnets, 4 masks
O 10.45.0.0/16 [110/65] via 192.168.1.1, 01:15:02, GigabitEthernet0/0
D 10.45.12.0/22 [90/2172416] via 192.168.2.1, 00:42:10, GigabitEthernet0/1
S 10.45.12.0/24 [1/0] via 192.168.3.1
C 10.45.12.128/25 is directly connected, GigabitEthernet0/2
Which two statements correctly describe how the router processes traffic destined to and interpret its routing table components? (Select two.)
- The router forwards the packet out interface GigabitEthernet0/2 because 10.45.12.128/25 provides the longest prefix match for destination 10.45.12.150.Answer
- BThe router forwards the packet to next-hop 192.168.3.1 because the static route has a lower administrative distance (1) than dynamic routing protocols.
- The bracketed numbers [110/65] in the OSPF route entry represent an Administrative Distance of 110 and a route Metric of 65.Answer
- DThe router forwards the packet to next-hop 192.168.2.1 because EIGRP has a lower administrative distance (90) than OSPF (110).
Answer
The router egresses traffic out GigabitEthernet0/2 based on the longest prefix match rule (10.45.12.128/25), and the notation [110/65] defines an Administrative Distance of 110 and a Metric of 65.
Traffic destined to 10.45.12.150 matches multiple entries in the routing table, but 10.45.12.128/25 has the longest prefix length (25 bits), making GigabitEthernet0/2 the elected forwarding interface. Additionally, standard Cisco routing table syntax formats protocol entries as [Administrative Distance / Metric], meaning [110/65] indicates an AD of 110 and an OSPF metric of 65.
Step-by-Step Solution
Key Concept
Routing Table Components and Longest Prefix Match Decision Logic