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 ...

I am really confused about the ICMP ping test. Can you explain this whether the continuous PING test affects the bandwidth, data flow and which is the best tool for monitoring the packet loss? As for ...

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 ...

So I recently upgraded my company's domain controller from Windows Server 2003 to Server 2008 R2. Naturally this resulted in a foray into IPv6, so I've spent some time delving into it and getting our ...

A journey through TCP/IP starts with the lower layers and works upward so that you can experiment en route to check your understanding. I'll start with Internet Protocol (IP) and the associated ...

Recently, I noticed that there has been a surge in ICMP packets between some of my Active Directory controllers and Exchange servers. Virus scanning proved that the servers were clean. Is there any ...

What are the minimum and maximum sizes of an ICMP packet? ICMP, the Internet Control Message Protocol, is a protocol used to test the connectivity between hosts or networks. The popular 'ping' command ...

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 ...

In its second IOS security bulletin in a week, Cisco warned that a common management protocol used on the Internet could be used to launch denial-of-service attacks against Cisco routers and other ...