One of the tools I looked at having for my expanding kit has been a usb wireless adapter that would work with minimal install on Windows/Mac or Linux. As you can imagine…. it’s not as straightforward as just getting one that’s compatible with Windows…. well, after much searching I found the D-Link DWL-G122 802.11g Wireless USB adapter…. (Revision B it seems is the one to get…) Anyway, using a generic driver downloadable for the Mac it will work (from ralink http://www.ralinktech.com). On linux, you have choices (isn’t that the truth…) anyway, there is a native driver (from ralink for the RT2571W/RT2671 chipset) and there’s the rt2x00 driver project and it’s also possible (and fairly easy) to install the Windows driver via ndiswrapper.
Category: Networking
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Is something up with ordb.org?
I’ve noticed several times in the last week a server of mine that is using postfix has rejected messages due to a failure in the lookup at relays.ordb.org. At first, I thought this was just a false positive in the database at ordb… but this morning I finally “caught it” while it was happening and went to pull up the ordb.org web page. It took…. 30-45 seconds and then proceeding to do a search on the rejected IP took another stretch. In looking at the logs it appears that there may be blanket rejections if the ordb.org check times out.
Here’s the postfix config setting….
smtpd_client_restrictions = permit_mynetworks,reject_rbl_client relays.ordb.org -
Good idea to help limit phishing attacks
I saw this a few weeks back and think it’s a good idea. Essentially why don’t we have a .bank domain registration and limit it to just financial institutions the way .gov is limited to government registrations. (and .mil for military, .edu for educational institutions…..) Let’s face it, anyone can register a .com .net or .org – maybe instead of increasing the number of Top level domains that ANYONE can register in, maybe we need to tighten the restrictions and add a few new TLD’s that would be more closely restricted. There’s already a .museum, .bank would be a good one next.
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Network swiss army knife
There’s no better way to say it, netcat is SOO useful, and there is an encrypted variation… cryptcat, you can do quite a few interesting and useful things VERY easily with these two utilities. (*It’s one of the utilities I used to image a live running system to a file on a network server.) The source is available from the previous two links. There are binaries for windows for both netcat and cryptcat available here, but with all such tools you should be wary of where a precompiled binary comes from.
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Vmware Server web interface tricks…
I haven’t been overwhelmed with VMware server’s web interface. You can start a virtual machine, or see statistics, but you can’t create virtual machines. Well, from the VMWare forums I did find a couple interesting “hidden” features. First, is a file manager at https://youriphere:8333/fm-properties and second is a GSX interface (which gives the ability to create a NEW virtual machine) at https://youriphere:8333/overview (the direct link to creating a new vm is https://yourip:8333/vmcfg-gsx )….
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Nxclient into xubuntu box
I like nx server and client, it can really make good use of low bandwidth connections to get a gui link. But, by default it’s quick and easy to setup gnome and kde login sessions within nxclient, but if you’re using xubuntu then you will need to setup a “custom” session and the command is startxfce4 …. so, start up nxclient, click configure and on the General tab, halfway down it should say Desktop, leave Unix and change KDE to custom, then click settings and check “run the following command” now, type startxfce4 and you should be set.
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Live filesystem “capture” into a virtual disk image
ah… the joys of *nix utilities…. I’ve just successfully tested a “capture” of a live, running system into a virtual disk image. No, I don’t mean that I booted up with an imaging utility. I took a live, booted and logged in system and imaged the primary hard drive that it was living on, into a file on another machine. (Yeah, I know, there are probably a few people reading this and saying they’ve done that and most people that would need to do this already know how…. sorry I missed the memo.) Not too long ago, VMWare released a tool to do something like this (that tool is for windows…) This should work on any platform that supports dd and netcat (although I’m not sure if piping output from one program to another works with a dos command shell – maybe cygwin would be a good environment to accomplish this with.) Anyway… here are the details.
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Scanning over the network, or sharing a scanner on a network
I remember the question from long ago, we had just shared a printer across a windows network and…. wait for it…. “oh, well could I share my scanner too?” On windows the typical answer was NO, at least not unless there was a driver from the scanner manufacturer that supported it, but on linux the answer is an unqualified YES as long as the scanner is supported under linux (so many are..) Using SANE (which is the linux scanner driver backend) you can share out scanners across a network and tips.linux.com has an article on just that topic. I’ve set it up before on my network and it was relatively easy to do and VERY convenient. At that time, I don’t recall a good functional windows client for the SANE driver, but it may have matured a bit by now (last I looked into it was 3-4 years ago.)
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Using DNS servers other than your ISP’s
As I mentioned earlier, Bellsouth seemed to be in the midst of a big DNS meltdown when I got up this morning. I spent some time getting various bellsouth customers “worked around” the issue by setting up an alternate DNS server for them. For starters…. DNS translates addresses like google.com into numbers (like 72.14.207.99) Think of it as a telephone directory lookup service… you can’t pickup a phone and punch in the letters of someones name to call them, you have to dial a number and first you have to see what the number is…. in networking, the computer does the DNS lookup for you when you type google.com in your browser bar. (Or when the browser tries to load it’s home page for instance.)
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Major Bellsouth DNS issues
This morning, I’m noticing some of the machines I monitor having big DNS problems. It seems to be Bellsouth.net’s dns servers gone sideways – none seem to respond. On one network in particular we’re having trouble getting a secondary (outside network) dns server to respond. From outside the bellsouth network things seem fine though. As usual dslreports is a good place to check if others are having the same issue. It appears as though this issue is affecting ALL of bellsouth’s network and has been since at the latest 11:30PM last night (the 16th of October.)