A sniffer is a device used to read, monitor and capture network data exchange between networking devices. These are generally used by network administrators to monitor the incoming and outgoing traffic in the network. It acts like a web filter, firewall tester and troubleshoots client-server relationships. If the packets are not encrypted, it gives you a full view of data inside the packet (passwords, PINs and privacy information). When the network is slow, we need to know the bandwidth of the network and is being used by whom. Sniffer can monitor the performance by hop-by-hop network path analysis and can minimize the downtime. If there is high traffic in the network it might be an indication of a hacker in the network, it can highlight the unusual spikes in the traffic. Here two sniffers are placed in between two routers to monitor the outgoing and incoming ICMP packets in a network.