When we began this series, we discussed the ICMP (Internet Control Message Protocol). This protocol is the basis for two widely used applications, ping and traceroute. In this lesson and the next, we ...

The current IP address scheme of 32-bit words is fast becoming inadequate. It would appear that 2 32 = 4 294 967 296 combinations of addresses should be enough for everybody, but in practice this is ...

Is it possible to allow ICMP4 for PMTUD into a NAT'd network? As far as my understanding goes simply allowing it to the firewall doesn't do much good as the firewall isn't responsible for ...

Generally, the way the ping command works amongst other network tools, is simply by sending special packets known as Internet Control Message Protocol (ICMP) Echo Requests to a target device, and then ...