There is an excellent discussion of the Blue Security DDOS attack here, including a copy of discussion from those behind the DDOS here. There is more information on Blue Frog and related issues on Wikipedia here. If you somehow missed this, it is probably in your best interest to be aware of what is going […]
Blue Security DDOS
Clearing Bad Messages Out of the Postfix Mail Queue
If you have bad messages in your Postfix mail queue, you can list them with the postqueue command: [root@svr-1 mail]# postqueue -p -Queue ID- –Size– —-Arrival Time—- -Sender/Recipient——- 4C63F2300BA 876 Mon Jun 5 09:31:54 user@somedomainsomewhere.com (connect to example.com[192.0.34.166]: Connection timed out) differentuser@example.com — 1 Kbytes in 1 Request. You will need the Queue Id to […]
Rejecting Email Based on Headers With Postfix
Postfix has the ability to reject mail based on regular expression matching in the header of the incoming mail message. To enable this, add these lines to main.cf: header_checks = regexp:/etc/postfix/header_checks header_checks = pcre:/etc/postfix/header_checks We stuck these after the alias line. Add the header content matches and actions to header_checks (usually in /etc/postfix) and restart […]
Tips on Running a Google Apps Pilot
When migrating from an internal email system to Google Apps, it’s nice to have the option of running a pilot program including a few of your users to try it out, and then to move the rest of the users over when problems with the transition have been identified and addressed. This is pretty easy […]
Samba Installation and Initial Configuration
We will install from source and get Samba up and running with one user and one share. We will not delve deep into the security, so as always, be careful, check the documentation, and do this in a lab first. We are assuming that Webmin is installed and running. First, download the latest version of […]
Samba Administration
Most of what can be administered in Samba can be done through the webmin module. You will need some other utilities as well. First, you are going to need a secure way to connect to the Samba box, and a way for your clients to change their password without using webmin. For your Windows boxen, […]
LPRM command
One thing that works very well in *NIX systems is the BSD style print queue. This is the style that comes with most Linux distributions. To list the print jobs in the print queue, type lpq. To remove a single job from your queue, type lprm -P{printername} {jobid}. For instance, if your printer name was […]
GNU Enscript
We ran across a cool utility called Enscript. It runs on most all platforms, but is most useful on *nix systems. If you ever just want to print a text document, but don’t want to load up an editor, you can use Enscript. Here is the GNU Enscript homepage. For example, to print a document […]
IPStor SAN/NAS
If you are considering any kind of SAN or NAS check out IPStor software by FalconStor. IPStor can be loaded on two Linux servers. These servers communicate with eachother and will failover automatically. They communicate via fibre channel or SCSI with storage devices (RAID cabinets, tape libraries, etc). They communicate with other servers (NT, Linux, […]
Managing Files With FileRunner
There are many filemanagers available for GNU/Linux; however, the one filemanager that has the most power for managing tons of files is the humble FileRunner. The fancy ones on KDE and Gnome aren’t entirely reliable, mainly, because they aren’t simple. They try and compete with XP by providing icons, previews, etc. That may be cool […]
Adding NFS Users
Add the hostname of the client you want to be able to access your NFS server to /etc/exports. To list the current allowed users: [root@mondo log]# exportfs /share u-1.signalq.com /share srv-3.signalq.com /share srv-44.signalq.com After adding the name to /etc/exports: [root@mondo log]# exportfs -a We added housey, now: [root@mondo log]# exportfs /share u-1.signalq.com /share srv-3.signalq.com /share […]
Point and Print in Samba
If you’re using a samba server to provide print services to Windows clients, why not take it one step further by offering point and print functionality. If you set this up, users *might* even be able to install printers themselves! At the very least it will save you time when you slave over their workstations […]
Default Admin Page for CUPS
Agatha broke her CUPS configuration when upgrading her Gentoo workstation. Simply deleting the old printer and creating a new one works. The thing about CUPS is that it just rocks, and only breaks, to our memory, during an upgrade. The configuration for the daemon is in /etc/cups/cupsd.conf. The cool web-based admin tool makes it really […]
Creating a SAN with iSCSI – Part 1 – Setting up the Target on GNU/Linux
[See This article for a newer procedure.] An iSCSI target is the server piece of an iSCSI SAN. The client piece/driver is called the initiator. We will be running the target on a GNU/Linux box with a 2.4.27 kernel, and will run the initiator on a Windows 2000 server. For our iSCSI target, we will […]
Creating a SAN with iSCSI – Part 2 – Setting up a Windows Initiator – Initial Install
We are going to create a drive that appears to the Windows 2000 operating system as a regular hard disk drive; however, this drive is actually a filesystem on a GNU/Linux box that is exported via TCP/IP using the iSCSI protocol. We created the server to do this in this article. Now, we need to […]
Creating a SAN with iSCSI – Part 3 – Setting up a Windows Initiator – Finish Install
You will see another license agreement box: If you agree, click Agree. You will be notified that the iSCSI initiator is installing: A box regarding the digital signature of the package will pop up: Click Yes if you wish to continue. If the iSCSI initiator installs successfully, you will see this box: A box with […]
Creating a SAN with iSCSI – Part 4 – Setting up a Windows Initiator – iSCSI Setup
You will see a dialog box saying the installation is complete: Click close. Open the Microsoft iSCSI Initiator program. There should be a shortcut on your desktop. If not, it is also in control panel. Open the Add Target Portal tab: The server we want is at 10.50.100.70. Click on the advanced button: The user […]
Creating a SAN with iSCSI – Part 5 – Setting up a Windows Initiator – Creating the Drive
You will see the name of the target in the box: Click Log On to connect to the drive and make it active. You will see a dialog: For now, just leave automatic restore option unchecked. Click OK. Now the available target box has the target listed as connected: Click OK and go into the […]
Creating a SAN with iSCSI – Part 6 – Setting up a Windows Initiator – Finishing Up
Our drive is detected properly now, and we have 3 gigs of unallocated space: Format the disk: If you want the drive to automatically be available at boot, check the box: Let’s copy a file over to our iSCSI drive: This drive is treated just like a hardware drive would be, but it is all […]
Configuring Print Margins With Alignmargins
There is a cool utility available from LinuxPrinting.org that can help align your margins. Below is how we configured our HP Laserjet 1200: [root@srv-1 usr-1]# cd /tmp [root@srv-1 tmp]# wget http://www.linuxprinting.org/download/printing/align.ps –07:04:32– http://www.linuxprinting.org/download/printing/align.ps => `align.ps’ Resolving www.linuxprinting.org… 216.129.135.176 Connecting to www.linuxprinting.org[216.129.135.176]:80… connected. HTTP request sent, awaiting response… 200 OK Length: 5,352 [application/postscript] 100%[====================================>] 5,352 28.10K/s […]
