Protocol analysers are good for admin work

Check for e-mail problems I use protocol analysers to monitor e-mail problems much more than I would have thought. To do this, you must set up an analyser with a filter that monitors the IP ports used by a mail server (typically port 25 for SMTP, 110 for POP3, and 143 for IMAP) to send and receive mail. Several good examples of how to do this are on packet-level.com. I've found the type of filter I described above to be useful in figuring out why a particular e-mail won't go through when the only error I get in the Exchange server logs is "communications error." I have made the modification to the filter that the site suggests, but this modification just examines e-mail to and from a particular mail server. However, this technique is still a big help because I don't have to go through an entire capture session to look for the mail traffic. Entire capture sessions can be quite large, depending on the size of your network. Verify that your firewall is working correctly Since firewalls protect your network from unwelcome visitors, knowing that they're working correctly is important for verifying the security of your network. Checking the firewall will involve using several different filters (these can be predefined filters, administer-created filters, or downloaded filters, all with various functions), depending on the level of sophistication of the packet filtering being used. In general, you will have two sets of filters, one checking packets based on outgoing traffic and one based on incoming traffic. Leaving the incoming filter running 24/7 would be a good idea, because this filter will be a good indication that the firewall is working as expected and will provide a quick alert if the firewall fails for some reason and begins letting unwanted packets through. For example, NetDoppler utilizes several features of the ICMP, IP, and DNS protocols to perform tasks and tests on remote hosts to check latency and throughput and to isolate problems. PacketScrubber removes sensitive or confidential data from frames and packets within a trace file by changing the packet and frame payloads to null data. Summary We've just scratched the surface of the possible uses of a protocol analyser. Before you go out and buy the first one you see or purchase something that a vendor recommends, try to obtain trial versions of a few, use them, and see which candidate best meets your needs. It's also a good idea to keep the analyser you buy under some type of maintenance contract from the vendor to keep the application up to date and problem-free. Editorial disclaimer: The authors and editors have taken care in preparation of the content contained herein but make no expressed or implied warranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for any damages. Always have a verified backup before making any changes.

Have your say instantly in the Tech Update forum. Let the editors know what you think in the Mailroom.

« Previous
1
2
3
Next »

Post your comment

In order to post a comment you need to be registered and logged in.

You can also log in with Facebook. Log in or create your ZDNet UK account below

By signing up for this service, you indicate that you agree to our Terms and Conditions and have read and understood our Privacy Policy. Questions about membership? Find the answers in the Community FAQ

ZDNet UK Live

All of the feedback regarding using a touch monitor for a desktop PC is right on. Several months ago, we installed a "demo" multitouch all-in-one...

2 hours ago by apexwm on Windows 8 could speed multi-monitor uptake

anyone wanting to triple boot *their* own Mac

3 hours ago by 191706 on xTreme Triple Booting: Linux, Mac & Windows

Cont.. Biggest Bugbear: Win7's stop-animate-go approach to work, you develop a staggered (not in the above alchohol sense of the word) approach to...

3 hours ago by SoapyTablet on Windows 8 could speed multi-monitor uptake

Ah the joys of Windows 8 Consumer Preview... If Windows 7 was 'Vista with Lipstick', whats Windows 8? Vista with Lipstick, the morning after?...

3 hours ago by SoapyTablet on Windows 8 could speed multi-monitor uptake

Though the metro look is quite cool on the windows mobile platform I think that think that microsoft ARE MESSING THINGS UP because what has they...

4 hours ago by daveveej on Windows 8 could speed multi-monitor uptake

I agree, we have a few touch screen monitors in work but as Windows7 and the applications we use are not touch screen friendly (the size of the...

4 hours ago by Custonian on Windows 8 could speed multi-monitor uptake

I find it amusing that Microsoft added the mouse, which was deemed awkward, but people were forced to use it so it stuck, and now they're saying,...

6 hours ago by archerthom on Windows 8 could speed multi-monitor uptake

Agree with other comments. Nobody's going to start reaching out to start tapping their desktop monitors with their fingers. Their arms would tire...

15 hours ago by BrownieBoy on Windows 8 could speed multi-monitor uptake

The only way a touch monitor would be any good is if it were horizontal on the desk, with a virtual keyboard so you could do away with that as well...

20 hours ago by Random_Error on Windows 8 could speed multi-monitor uptake

This is just dumb! Forget that I think Windows 8 will bomb, but really, people are going to go out and buy touch Monitors now??? Just pretend...

22 hours ago by JBDragon on Windows 8 could speed multi-monitor uptake