Network PC World

Traceroute is a network diagnostic tool used to trace the path packets take from a source to a destination. It functions by sending packets with incrementally increasing Time-To-Live (TTL) values and receiving responses from routers along the way, allowing users to identify the hops the packets pass through. Here’s how it works on different platforms: Windows (ICMP-Based Traceroute) : Protocol : Uses ICMP at Layer 3. How It Works : Windows sends ICMP Echo Request packets with increasing TTL values. When a router receives a packet with a TTL of 1, it decrements it to 0, drops the packet, and returns an ICMP Time Exceeded message to the source. Each hop responds with this message, allowing the traceroute to document the routers. Final Step : When the packet reaches the destination, it sends an ICMP Echo Reply instead of a port unreachable message, as it's based on Layer 3 only. Unix-Based Systems (UDP-Based Traceroute) : Protocol : Uses UDP at Layer 4. How It Works : Unix-based syste...

Traceroute is a network diagnostic tool used to track the path packets take from a source device to a destination across an IP network, helping identify routing paths and any potential delays or failures. Here’s how traceroute works: ICMP and TTL (Time-To-Live) : Traceroute sends packets with an initial TTL value of 1. The first router the packet encounters decrements the TTL by 1, causing it to reach zero. When the TTL hits zero, the router discards the packet and sends back an ICMP "TTL expired" message to the source. This helps the source router document the identity (IP address) of the responding router as part of the path. Incrementing TTL : Traceroute then increases the TTL by 1 for each subsequent packet. The second router will forward the packet to the next hop until the TTL expires, at which point it also sends a TTL expired message back to the source. The process repeats, each time documenting the responding ...