Which criteria are routing decisions based on?

All routing decisions are based on the destination IP address. The router examines the IP address and routes the packet to the next closest hop for the network it belongs to. The source IP address is not used during the route process and will not change throughout the process. The time to live (TTL) is used to limit how many times a packet is routed throughout a network or the Internet. The TTL is decremented by 1 as it passes through a router; when it reaches 0, the packet will be dropped and will no longer be routable. The destination MAC address is not used for routing decisions.