Friday, November 10, 2006


Well, I know 64-bit computing isn't new, but it is new for me. Even though I had 64-bit hardware available, I've always installed 32-bit version of the OS (linux on x86_64).

I had to deal with an x86_64 CentOS 3 server and I liked it. It just took some time to figure out how to install 32-bits packages. yum install package.arch (package.i386).

Pretty neat! I just can't say anything about the performance as of now.

Friday, November 03, 2006



A few words on milter-greylist, especially because the new version (3) is now RC6 and looks pretty stable. What are the features of milter-greylist?
  • Per-domain and per-user settings.
  • Friendly networks whitelisting
  • Multi-MX sync (database is replicated many mail servers if needed)
  • SMTP-AUTH support
  • SPF records: can be configured not to impose GreyListing to messages that are SPF-compliant
  • Access lists with DNSbls
This last option is new in version 3. It is very nice: it allows one to configure milter-greylist to impose GreyListing if the source IP is on (configurable) DNS black lists (DNSbls).

I've installed it and it decreased the number of messages/day by about 60%. I only had to whitelist one server.

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Just a little reminder to help open-source project by donating. Almost every project needs funding and it is easy to donate. My latest donations? Mondorescue, CentOS, PfSense, UltraVNC.

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PfSense Follow-Up II


Lasts week, I installed PfSense RELEASE 1.0, and it has been running very smoothly since the install. No more crashes! It's been running for 7 days straight now and I had absolutely no problem with it, except for my VoIP config for static port (see my other PfSense posts). Thanks a lot to the PfSense team!

I just upgraded to 1.0.1 now...

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I've been using UltraVNC for a while and while commenting on an article on UnixTutorials, I thought it would be a good idea to share my knowledge. First, I must say that UltraVNC is a free version of VNC that has more features than the free version of RealVNC (thanks for sharing the code, though...). It supports encryption and Active Directory authentication, and a few other nice features.

But what I want to talk about today is the Single-Click feature (SC). Very useful... Example situation: One of your client went to a foreign country and he wants to configure the e-mail client of a laptop he borrowed there. VNC is not installed. You can spend an hour telling him over the phone how to configure Outlook or Thunderbird, or just tell him to go to your website, download a single executable, and take control of the PC and configure it.

How to proceed:

  1. Make sure the VNC (or UltraVNC, for the rest of the text) viewer is loaded on your computer, in listen mode. You can access a shortcut in the start menu for that. It will then listen on port 5500 for incoming connections from a VNC server.
  2. Set your firewall so that it forwards port 5500 TCP to your machine (may be usefull to have a DHCP reservation, to avoid problems).
  3. If you don't have a static IP address with your ISP, you should open a free account with Dyndns to get a FQDN that always points to your IP address, even when it changes.
  4. Create an UltraVNC executable. Go to for the instructions. Basically, you download a zipped template, you edit the configuration file (helpdesk.txt) for your setup (the only mandatory edit is to tell your IP address/FQDN, the rest is aesthetic. Once your edit is ok, you then go to the UltraVNC Creator Tool, and it will make you an executable out of your config.
  5. You send the .exe to your family and friends, or, even better, you put it up on your website, so that anyone who has access to the internet can download the file. Internet connexion is a requirement for remote control over the internet, after all, so they shouldn't have problem downloading the file!
  6. Once it is downloaded, the user has to execute the file, then select the desired options (Tech support from home, from office, with encryption or not...) since in one executable, you can configure more than one targets.
  7. You are now prompted if you want to accept or not the remote control request.
  8. If you like the product, think about donating to the UltraVNC team (I'm not one of them, and, yes, I did donate).
  • The executable is linked to one set of targets, you cannot change it without creating a new executable.
  • You must have control over the firewall protecting your private network.
  • It takes some time to create and fine-tune the executable, but it is definitely worth it!
I hope this is all clear. If you have questions, please don't hesitate to ask them here, I'll be glad to answer them.

* By the way, if VNC is installed on the remote machine and steps 1 and 2 are done, you can just tell the remote user to right-click on the VNC server icon in the system tray and select "Add new client". Then they just put your FQDN or IP address (you can use to find it out) in the hostname field, then click ok. You're directly connected, no prompt.

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