Data is sent across the internet in packets.
Describe how a router uses an IP address to send a packet towards its destination.
Mark scheme
Award up to two marks for a linked description such as:
- Reads the destination IP address from the packet (1) to choose the next router/network on the path (1)
- Uses a routing table that holds destination IP addresses/networks with the matching next hop (1) to forward the packet on the best/quickest route (1)
- Forwards packets from one network to another (1) that is closer to the destination IP address (1)
- Checks the destination IP address against its stored routes (1) so the packet is sent out towards the correct network (1)
Allow 'next hop' / 'next router on the route' / 'next network' / 'gateway' as equivalent wording for where the packet is sent next.
Do not accept answers that only say the router sends the packet to the destination.
Do not accept answers that say the router converts/changes the destination IP address into a MAC address and sends the packet straight to the destination, as no routing step is described.
Example answers and how they were marked
The router reads the destination IP address in the packet and uses it to forward the packet to the next router on the route.
Why: Linked point (1): reads the destination IP address; development (1): uses it to choose/forward to the next hop on the route.
It reads the destination IP address on the packet.
Why: Point only (1): reads the destination IP address; no linked development about forwarding to the next router/network.
The router changes the destination IP address into a MAC address and sends it straight to the destination.
Why: No creditworthy point: it says the IP address is changed into a MAC address and the packet sent straight to the destination, which is neither reading the destination IP address to choose the next hop nor forwarding between networks. This is the answer excluded by the 'Do not accept' line.