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Difficulty: MediumIPv4 Static Routing

A network administrator is configuring static routes on router R1 to reach two remote networks: Subnet A (10.2.2.0/2410.2.2.0/24) connected across a point-to-point serial interface (Serial0/0/0), and Subnet B (10.3.3.0/2410.3.3.0/24) connected across a multiaccess Ethernet interface (GigabitEthernet0/0, with next-hop IP address 192.168.1.2192.168.1.2). Which two static route configuration commands follow Cisco IOS best practices and prevent unnecessary ARP resolution overhead?

  1. ip route 10.2.2.0 255.255.255.0 Serial0/0/0Answer
  2. ip route 10.3.3.0 255.255.255.0 192.168.1.2Answer
  3. C
    ip route 10.3.3.0 255.255.255.0 GigabitEthernet0/0
  4. D
    ip route 10.3.3.0 0.0.0.255 192.168.1.2

Answer

The two correct static route statements are 'ip route 10.2.2.0 255.255.255.0 Serial0/0/0' for the point-to-point serial connection and 'ip route 10.3.3.0 255.255.255.0 192.168.1.2' for the multiaccess Ethernet connection.
In Cisco IOS IPv4 static routing, the ideal syntax depends on the physical media type of the outgoing interface. For point-to-point links like Serial interfaces, referencing the exit interface directly is complete and efficient because there is only one potential receiver on the segment. For broadcast multiaccess links like Ethernet, referencing the next-hop IPv4 address is mandatory for clean Layer 2 frame encapsulation without generating excessive ARP broadcasts.

Step-by-Step Solution

1
Determine the interface media type for Subnet A (10.2.2.0/2410.2.2.0/24).
Subnet A uses a point-to-point serial link (Serial0/0/0).
On point-to-point links, specifying the local exit interface directly avoids next-hop IP recursive lookups without causing Layer 2 MAC resolution issues.
2
Determine the interface media type for Subnet B (10.3.3.0/2410.3.3.0/24).
Subnet B uses a broadcast multiaccess Ethernet link (GigabitEthernet0/0).
On Ethernet networks, specifying the next-hop IPv4 address (192.168.1.2192.168.1.2) allows the router to resolve the specific next-hop gateway MAC address, preventing proxy ARP overhead.
3
Verify Cisco IOS syntax compliance.
Confirm standard dotted-decimal subnet mask formatting (255.255.255.0).
Cisco IOS static routes mandate subnet masks ('ip route <prefix> <mask> {ip-address | exit-interface}').

Key Concept

IPv4 Static Route Syntax and Next-Hop Resolution on Point-to-Point vs Multiaccess Interfaces
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Topics

IPv4 Static Routing

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