Readers' Forum - November 2003

by Rob Zorn
from the November 2003 Newsletter

If you'd like to ask a question or request some help on any Actrix or Internet-related matter. Simply send me an e-mail with the word "forum" in the subject line. I'll try and answer your question by return e-mail, and will also post the answer here for the benefit of others who may have a similar question or problem. By the same token, if you read something here and think you may have something to suggest, please feel more than free. Please also note that questions and answers may turn up under the Helpful Tips section on the Actrix home page (www.actrix.co.nz).

I'm really grateful to my support team, too, for their input here when some of the questions also have me a little stumped.

Allen asks, I was wondering if you could at some stage cover 'pinging'. What is it, why do people do it, can you do anything to stop/minimise it? Over recent weeks I have noted constant 'pinging' from when I first log on right through until log off. I would like to understand this 'phenomenon' and if it can be stopped. 

This is a good and interesting question about which lots could be written. I'll try and cover the main parts of your question, and add extra detail where I think it might be of interest or assistance.

A ping is probably the quickest way one computer can talk to another over the Internet. Basically, if you use your computer to ping another one, you are sending that other computer a very small amount of data and asking it to respond by sending that small amount of data back to you. Typically, a ping is one packet of data, which amounts only to a few bytes (normally 32).

Anybody can ping. If you have a Windows machine, click Start/Programs/Accessories and then click either DOS Prompt or Command prompt. Make sure you are online and then type in ping "www.google.com" (without the quotes). When you hit enter, your machine will ping the Google server four times. Your machine will then report to you that it sent Google four packets. It will tell you how many times Google successfully sent the packets back, and give you an average number of milliseconds it took for each of these returns. Technicians use this process to see whether a certain machine or web site is up, and to get an idea of how good the traffic flow between their network and the other machine is.

This is the typical legitimate use of the ping process. People can also use pinging for the purposes of evil. Sending 4 pings to Google is not a problem. Web servers can handle responding to many many pings at a time, but they aren't eternal in their capacities. You can perform a denial of service (DoS) attack on another machine by pinging it very fast and relentlessly. If you "flood ping" a web server, for example, it becomes so busy answering your pings that it can't serve web pages up anymore. You are tying up all of its resources. Typically, a denial of service attack will be co-ordinated so that lots of hijacked machines are flood-pinging the same poor victimised computer. Note also, that there are other ways of performing DoS attacks besides using pings.

Getting back to your question... I assume you are using Zone Alarm or some similar type of firewall program and it is reporting to you that you are being pinged. Most machines connected to the Internet are probably being pinged from time to time and if people aren't running a firewall such as ZoneAlarm, then they probably don't even know, because a computer won't usually report when it is answering pings. It is just something it is programmed to do.

Why might you be receiving these pings? There could be any number of reasons.

Firstly, if you're connected to a peer to peer (P2P) network such as Kazaa, you will probably be getting pinged a lot. This is so that others who may want to download files from you can get an idea of how well they would be able to connect to you before they decide whether or not to do so. Depending on which P2P program they are using, you may be getting pinged by the network every time someone searches for a file you have, or by the individual user at the other end. You might get a similar result from being connected to IRC (Internet Relay Chat).

Secondly, you could just be part of a "scatter-ping" which could hit you even when you aren't connected to any of the above. If you're on the Internet, your computer has an IP Address which is a series of numbers used to identify it. A hacker looking for potential victims might be pinging a whole range of IP Addresses looking to see what sort of returns he gets. This way he knows what machines are out there and which ones have fast connections (cable or DSL). Computers with fast connections make much better hacking targets for all sorts of reasons.

Unfortunately, you can't really do much about it. There is no way to stop other people pinging across the Internet. However, you can use a firewall program such as ZoneAlarm that overrides your computer's natural willingness to answer pings. ZoneAlarm and similar programs will absorb the pings sent to you and refuse to send any data back. This means that the person doing the scatter-pinging gets no indication you are there at all, making you much less likely to be a target. The unfortunate side-effect of this is that ZoneAlarm will often be popping up the little window informing you that you've just been pinged and that it has been of great service to you by denying an answer.

In Outlook Express I can empty the deleted file in one go by selecting --empty deleted box-- however this does not seem to be available in the inbox or in the sent items file, where I have to delete the items one by one. Is there a way in altering the settings, so I can empty those files in one hit as well? I use WindowsXP and outlook express 6. Looking forward to your answer, Bert.

Yes, the Edit/Empty 'Deleted Items' Folder command is a handy one for permanently deleting the entire contents of your Deleted Items in one go. Unfortunately, that command cannot really be duplicated for other folders within Outlook Express.

However, all is not lost. You don't have to delete items from your inbox and/or other folders one by one.

If you want to select several e-mails to be deleted, select one by clicking on it. Hold the Ctrl key down and click on another one. You'll see that both become selected. You can keep going, selecting as many more as you like by keeping the Ctrl key held down while you click to select more e-mails. Once you've done that, click the Delete button and all the selected e-mails will be moved to your Deleted Items folder.

You can also use the Shift key to select a block of e-mails. Say you had ten e-mails in a row that needed deleting. Select the first one, then hold the Shift key down and select the tenth e-mail. You will see that all the e-mails in between get selected as well. They can then be sent to your Deleted Items folder all at once by clicking the Delete key.

Lastly, if you do want to send the entire contents of your inbox (or another folder) to the Deleted Items folder, select any e-mail in the folder by clicking on it once. Then, using your keyboard, hold down the Ctrl key and press the A key. This is the Windows "select all" command. Every e-mail in your folder will now be selected, and you can use the Delete key to send them all to your Deleted Items folder in one go.

Once you've gotten everything into your Deleted Items folder you can use the Edit/Empty 'Deleted Items' Folder command to delete everything permanently. Once this last step is done, though, you can never get those e-mails back.