What action does a host take when it needs to send a packet to a device on a remote LAN with no ARP cache mappings?

What action does a host take when it needs to send a packet to a device on a remote LAN with no ARP cache mappings?

• A. It will drop the packet.
• B. It will send a ping request to the device.
• C. It will send an ARP request for the MAC address of the default gateway.
• D. It will attempt to connect directly to the destination device.

Answer: (C)

When a host needs to send a packet to a device on a remote LAN and does not have ARP (Address Resolution Protocol) cache mappings, it will send an ARP request for the MAC address of the default gateway. This process is crucial because, for a device to communicate with another device on a different network (remote LAN), it must first send the packet to its default gateway, which is responsible for routing packets to other networks. The ARP request is a broadcast message sent out on the local network segment, asking for the MAC address associated with the IP address of the default gateway. Once the host obtains the MAC address of the default gateway from the response to its ARP request, it can then encapsulate the packet intended for the remote device and send it to the default gateway. Understanding this process is essential for effective networking, as it highlights how hosts communicate over networks and the role that ARP plays in resolving IP addresses to MAC addresses when routing to different network segments.

When a host needs to send a packet to a device on a remote LAN and does not have ARP (Address Resolution Protocol) cache mappings, it will send an ARP request for the MAC address of the default gateway. This process is crucial because, for a device to communicate with another device on a different network (remote LAN), it must first send the packet to its default gateway, which is responsible for routing packets to other networks.

The ARP request is a broadcast message sent out on the local network segment, asking for the MAC address associated with the IP address of the default gateway. Once the host obtains the MAC address of the default gateway from the response to its ARP request, it can then encapsulate the packet intended for the remote device and send it to the default gateway.

Understanding this process is essential for effective networking, as it highlights how hosts communicate over networks and the role that ARP plays in resolving IP addresses to MAC addresses when routing to different network segments.