A host computer has an IP packet of data it needs to send to another computer that’s on the other side of the world—how does it get there? Like the workers at postal service hubs, routers look at the incoming and outgoing locations of the IP packet so they can determine the shortest and fastest route to the final destination. Just like our homes and businesses have mailing addresses, each host on a network has its own IP address. Your computer’s IP address is assigned to you by a router, which is connected to another larger router on the internet. A router routes data from IP address to IP address, just like the postal workers route letters from address to address.
All routers and hosts on the internet are connected through different paths, and each of these stops has its own IP address.
Each router has its own routing table that records the paths each packet of data should take to travel to its destination. Routes in these tables can be static or dynamic. A static route is a route that doesn’t change—meaning, if you send data from one address to another, that data always takes the same path. For example, if you always drive to the grocery store on the freeway and never take the backroads, you drive a static route to the grocery store. If you choose your route to the grocery store based on traffic conditions, you drive a dynamic route. A dynamic routing table updates automatically based on the shortest and fastest path to a destination.
Once a router determines that the address is on its own network, it will deliver the data. Then, if requested, the destination computer will send data back to the original address—a process that also uses IP routing. The path between two IP addresses might be different from one moment to the next based on different factors, including latency—if a router detects that the shortest path isn’t the fastest, the data may travel through more routers to get to its destination. [1] X Research source
The first IP address on the route is the IP address of your own router, also known as your default gateway IP address. You can also find this address by going into the Command Prompt and typing ipconfig/all. The second address is the router that your own router decided to send the packets next. This IP address likely belongs to your ISP, although if you’re on a larger network (such as your work or school), your packets may go through several internal routers before reaching your ISP. The three columns with numeric values display the time (RTT) it took for your packet to reach that router and return to your computer. The values are displayed in milliseconds (ms). If some hops have significantly larger times, that could indicate latency at that locations. In general, anything less than 150ms is considered acceptable. [3] X Research source If you see an asterisk instead of a numeric value, that usually indicates packet loss, or dropped data. However, if you see nothing but asterisks at the destination and the traceroute completes successfully, this could mean the target address’s firewall is blocking the request.
