Archive for October, 2005

How to build a ‘for loop’

Tuesday, October 18th, 2005

How to build a for loop

There are many tools in programming to control when certain commands are run.  Different tools operate in different ways. A for loop is a programming language statement which allows code to be executed over and over until a specific condition is met.  This particular  statement  explicitly distinguishes a loop counter or variable.  This means that the loop is does not wait for a  test condition to start operating, it waits for a condition to stop executing.

The syntax for this loop is as follows:

for  item in some_iterable_object:
doSomething
doSomthingElse

A for statement has the same structure in many programming  languages.   All for loop statements make use of INTEGER variables. This means that you do not need to declare the initial value as an integer variable.

The first line of the command contains  the initial value statement;   An integer value, usually the number 1
followed by the test condition statement;  using logical statements such as  < ( less than )  = (equal to)  > (greater than)
ended by the increment statement; which increases the value of the integer by one.

for (counter = 1; counter <=5; counter++)
//statement;

In the example above  the initial value statement sets the variable  counter  equal to the integer 1, the test condition then looks to see if that counter variable still qualifies to be less than or equal to 5,  which it does,  so it increments the variable to 2 and then executions the commands in the statement.

It loops and tests the value or counter again  ( 2 is less than 5 )  it increments it to 3 and runs the command again.

In its simplest form this basically tells the program to execute the statement 5 times.   In practice a programmer will engineer the executed statement to use the  counter variable to run through a series of values.

so if I have a series of variables.   a1, a2, a3, a4, a5 etc…

I can create the statement to apply some operator or math function to the variable.  For example

for (counter = 1; counter <=5; counter++)
“a”+counter = random(100);

This example would  iterate through all 5 variables and set their numerical values to a random number between 0 and 100

Through more complete statements you can nest all sorts of logical commands.

 

Troubleshooting Link Aggregation in Mac OS X

Sunday, October 9th, 2005

Mac OS X 10.4 includes support for link aggregate networking. Link aggregate networking shares network traffic over two or more bonded Ethernet controllers, giving them one IP address for communication. This can allow the servers controllers to run at speeds of 2Gbps. Link aggregation is configured using the Network System Preference Pane.

To enable Link Aggregate Networking
1. Open the Network Pane from System Preferences.
2. Click the Show: box and select Network Port Configurations.
3. Click New.
4. In the Name: box enter a name for the new aggregate port.
5. In the Port: box select Link Aggregate.
6. Places check marks in the boxes for each port you would like to aggregate.
7. Click OK.
8. Configure the Port as you would any other network port.

Troubleshooting
Link Aggregate Ports must be used in conjunction with an Ethernet Switch.
Link Aggregate Port status can be viewed for each en adapter using the status tab in Network Preferences for the controller.
Assigning multiple LAN IP addresses to a Link Aggregate port can be tricky. I’d stay away from this if possible.
Do not assign two LAN IP addresses to a Link Aggregate port if they are not in the same IP scheme/subnet.

Sharing Exchange Calendars

Friday, October 7th, 2005

When users have personal calendars they want to share the work gets done on the workstations to grant access.

There are 2 locations that access needs to be given to. The first is the mailbox. The typical setup is to make this user a reviewer. The second location is the specific folders that need access. This can be given in various degrees, but if the user needs to make changes (delete, add, move) then the user being given access should be made into an “owner.”

In the latest revision of Office, you can actually do the second step from the “delegate” tab of options. However, the delegate still needs to be given reviewer access to the mailbox, as this is above the actual folders in the tree.

There are 2 ways to gain access into a calendar or contact folder you’ve been assigned delegate access to. The first and best is from your Exchange tab in your account settings. You can add mailboxes you’ve been given access to and they will appear in the folder list showing only the folders of the mailboxes you’ve been given access to.

The second way is to go File, Open, Other Users Folder. If you do this, it will be closed the next time you open Outlook, so this is only good for temporary access.

Delegate access is NOT assigned from the Exchange Admin interface with the exception of Public Folders. These are different than sharing the folder of a user. In Public Folders on the Exchange Admin interface, you will see the folder and you can assign permissions for these directly. These permissions should never be altered from a client.

Microsoft Releases Service Pack 1 for Microsoft Exchange Server 2003

Thursday, October 6th, 2005

Microsoft Releases Service Pack 1 for Microsoft Exchange Server 2003
Charles Edge

SP-1 is a collection of fixes, enhancements, and updates to Exchange 2003 designed to extend the stability and features of Exchange. Overall, this update should fix some of the smaller, more pesky issues and should also improve some of the features that users have been looking for. In addition, the security of Exchange has been slightly enhanced and new tools have been added.

Before SP-1, obtaining the fixes for Exchange 2003 that are included in SP-1 meant making a support call to Microsoft Support. Now all of the general release hot-fixes and patches as well as the private patches are available in one download.

In addition to the patches, SP-1 has new features, including:

• Outlook Web Access and Outlook Mobile Access Enhancements
• Enhancements were made to Outlook Mobile Access user interface, including out-of-office modification, a bigger text entry field, search folder support, and different menus
• Exchange System Manager can be used to merge or copy a restored mailbox without using ExMerge – very nice feature
• “Move Mailbox Wizard” allows the movement of mailboxes across groups
• The Migration Wizard supports Profile Update Tool, which runs on a user’s computer and updates his or her Outlook profile
• An admin can now move public folders, mailboxes, distribution lists, and contacts inside sites
• Exchange support for Shadow Copy
• Performance of Exchange 2003 on HyperThreading has been improved
• Badmail folder usage is disabled due to security risks

SP-1 also contains new tools for Exchange. The following are available as separate downloads:

• Exchange Domain Rename Fixup
• Exchange 2003 Management Pack Config
• Outlook Web Access Web Administration
• Exchange Server Profile
• Updated Exchange 2003 Deployment
• AUTD Binding
• Auto Accept Agent
• Badmail Deletion and
• E-mail Journaling Advanced Configuration

Installing Adobe CS

Thursday, October 6th, 2005

When installing Adobe CS, it is best to log in as an administrator, rather than as a regular user and then authenticating at the installer prompt. Adobe CS’ automated updater will only run when you are logged in under an administrator account. Otherwise, you will have to download and install all of the individual updates manually. The whole installation process will take at least one hour. There are approximately 70MB worth of updates that are not available as a standalone installers.

In situations where CS2 (or CS1 for that matter) will be installed on multiple computers, you can speed up the process considerably by making .dmg files from all of the installer CDs and installing the software from mounted disk images. It’s especially fast when the .dmg files are on the local machine, but plenty quick from a shared volume too. Generally, if you have dmg files on a file server you cannot have more than one computer mount each image at a time. However, if you create the images as read-only, it may be possible to have more than one client open the dmg remotely at a time. Otherwise copy it to the local machine from the server.

Deleting FTP Users in Mac OS X Server

Thursday, October 6th, 2005

Remember, in OSX both User Names and Passwords are Case
Sensitive

Open Workgroup Manager
Click on the Sharing Button
Click on Share Points Tab
Select the directory you will be removing
On the General Tab, uncheck “Share this item and its contents”
Click Protocols and select Apple File Settings, uncheck the box for
“share this item using AFP”
Click Protocols and select FTP Settings, uncheck the box for “share
this item using FTP”
Click the Save button
Click Accounts at the top of the screen
Click on the Users Tab, select the user to delete
Delete the user, answer Delete when prompted
Click on the Groups Tab, select the group to delete
Delete the group, answer Delete when prompted
Open the FTP root directory (there is an alias on the servers desktop,
otherwise it is located in /library/ftpserver/ftproot)
Delete the alias to the directory we will be deleting, if it is listed here
Open the FTP drive, find the directory, and delete it
Typically, it is advised to leave this directory in the trash for a little
whileto ensure there is no data that will be needed later (a week is wise)

The MalWare Cat and Mouse Game

Wednesday, October 5th, 2005

Spyware is software that covertly gathers user information through the user’s Internet connection without their knowledge, usually for advertising purposes. Adware refers to any software application or program displaying advertising banners or Pop-up. Adware is often considered spyware (although not always) and is typically installed without the user’s knowledge. Malware is a general term that encompases both of these and often viruses and trojan horses, which can cause computers to become slow due to the amount of processing power that these applications can take and the number of them that can infect computers.

Malware applications are typically bundled as a hidden component of shareware programs, online music, scripts hidden on websites and viruses that can be downloaded from the Internet. Over the past two years, many products have been released such as Windows XP Service Pack 2, Adaware and Spybot Search and Destroy that can effectively remove spyware. However, spyware and adware authors were able to make a lot of money from their pseudo-legal actions and have become better programmers in their newfound spare time.

Many spyware and adware products have begun to incorporate the use of root kits into their software. A root kit is a set of tools used by intruders once they have hacked into a computer system. These tools can help the attacker maintain his or her access to the system and use it for malicious purposes. Root kits often discuise themselves in order to prevent detection. Root kits exist for a variety of operating systems such as Linux, Solaris, and versions of Microsoft Windows. Root kits are typically used by attackers to build collections of slave systems and hide their tracks.

By using techniques that are most commonly attributed to attackers, spyware and adware products are becoming more and more harmful to systems. The utilities that once helped to resolve malware issues on systems are not working as well as they once did because of these new techniques employed by malware authors. Many of these techniques go far beyond simply hiding the malware and involve teaching the operating system to pretend that the malware doesn’t exist to make it almost impossible to find.

RootKit Revealer is a free product distributed by sysinternals.com that can search for known root kits. A litmitation of this application is that it doesn’t find new attacks that were released since the last revision of Rootkit Revealer. Microsoft is also looking into software that can detect root kits with their Strider Ghostbuster Project. Both RootKit Revealer and Strider Ghostbuster not only look for root kits but also look for any attempts to hide any applications from the operating system.

This was effective when the projects were announced and first released. Now, a new generation of malware is coming along that is intelligent enough to actually hide itself from standard searches and then not hide itself from the RootKit Revealer or Strider Ghostbuster scans. The finesse with which authors of malware are creating their root kits often leaves one wondering who is ahead in the game.

For more information on the many rootkit removal services that may be available to your business, please contact Three18, Inc. at 310-581-9500 or via email at sales@318.com