NetGong is a desktop tool that periodically performs checks on remote computers to check that they're working OK. You provide it with a list of devices to check, a basic schedule for doing the checks (basically the number of minutes to pause between checks) and the action(s) to take in the event of a problem. The latter includes alerting you by playing sounds, displaying an on-screen message, sending an email, or running a script; you can also configure it so that it stops bombarding you with messages after 'n' occurrences, and also to alert you when a problem goes away.
The actual checks it makes can take two forms: the most basic is a simple "ping" of the remote system, or you can be a little more advanced and tell it to attempt to make a connection on a given TCP or UDP port (so you could, for example, tell it to try making a connection on port 25 to your mail server in order to verify that it's accepting SMTP connections).
NetInfo is a collection of 15 network utilities, all bundled into a single application with one tab page per utility. "Local Info" tells you about all the interfaces on your computer – what they're called, what the IP address is, details of the DHCP server they used to get their settings, and so on. Think ipconfig /all and you'll get the idea. "Connections" is a pretty version of the netstat utility, and tells you about the network communication sessions currently active on your computer.
"Ping" and "Trace" are the old faithful for checking that remote computers are up, and "Lookup" allows you to enter a hostname and have its detail looked up from the DNS. "Finger" is a client-end application for the Unix finger server, which is used to fetch the details of someone's login ID on a remote Unix system (and which is turned off on servers run by anyone with any sense, so is often of little use).
"Whois", when given a domain name, looks up that domain's registration details in the global database; in fact the implementation here is pretty clever, since different top-level domains (eg. com or co.uk) need you to look at different Whois servers, and NetInfo dealt with this seamlessly when we tried it. "Daytime" returns the local date and time at the server you point it at – if that server has been configured to respond to such requests. "Time" is an NTP client – point it at an NTP time server and it will pull down the current date and time, and "Quote" returns "quote of the day" style quotations from remote servers.
"HTML", given a URL, pulls down and displays the raw HTML for that URL, and "Scanner" scans a user-provided IP range to find hosts that are up and listening on addresses in that range. "Services" takes the "Scanner" concept a step further – given a hostname or IP address, it does a port scan on the remote device. Finally, "E-Mail" tells you about the mail servers for the given address, including their addresses and relative priorities, and also contacts the server(s) so it can report the greeting each server gives - which, much of the time, tells you what make of email server package they're using. There's an additional "Web Center" tab, which gives access to versions of the various tools which are running on remote servers rather than on the local host.
NetGong is a handy little "heads-up" tool that will let you know when something has gone a bit awry in the network. It's a very good tool given the price, though I reckon you'd be more likely to run it on a machine in your comms room than on your day-to-day work computer so you don't get bothered all the time with bongs, squeaks and pop-ups.
Initially I thought NetInfo was going to be a pointless waste of time – after all, I'm perfectly capable of typing ping blah.com or ipconfig /all in a DOS box, and frankly I can live without a quote of the day and without knowing what the local time is on some weird server somewhere. Actually though, some of the tools are extremely useful.
For instance, while trying out the "Time" function, I discovered that the timeserver my PC points to simply wasn't working much of the time. I also discovered that I do have at least half a brain, because running the "Services" scan on my client's mail server showed that the only ports with services on them were the ones I wanted to be there.
The "E-Mail" function is dead handy for doing a quick but complete lookup of how someone's email servers and their corresponding DNS entries are arranged. And the raw HTML download in the "HTML" section would have been very handy to me last week in my day-job as a freelance developer – in fact, only last week I wrote my own tool for showing the raw HTTP results from a Web page access, because I didn't know of something that would do it for me.
In short, then: NetGong is handy and cheap, and NetInfo, despite initially looking pretty pointless and having a few pointless features, is a really handy set of utilities. So much so that I've just spent my own hard-earned cash and bought a copy.
You can do most of what these programs do without needing to buy them, and usually you can do it with built-in Windows functions, but particularly with NetInfo, wrapping them up into a bundle really adds value and usability.