TweetFollow Us on Twitter

Troubleshooting Directory Services

Volume Number: 23 (2007)
Issue Number: 06
Column Tag: MacEnterprise

Troubleshooting Directory Services

The basics

By Philip Rinehart, Yale University

Directory Services

One of the most common questions that are discussed on the MacEnterpise mailing list is the diagnosis and analysis of integration of OS X with Directory Services. While most commonly talked about in reference to Active Directory, many of the tools that can be used are applicable to any Directory Service, as most rely on the same core foundation. The first step of any analysis and troubleshooting is based on having a solid Domain Naming System, commonly known as DNS.

DNS problems

How does one go about troubleshooting DNS on OS X? More importantly, what should be tested and in what order? Checking forward and reverse DNS records usually makes the most sense initially. Misconfigured DNS information can often be the root of Directory Service problems. If the administrator configuring DNS has not correctly set both the forward and reverse DNS records, any attempt to bind or use a Directory Service becomes incrementally difficult.

Testing forward DNS

The first step is to test forward DNS records. As a brief reminder, forward DNS is the process of looking up a domain name and having the IP address returned. There are many tools to test this functionality, but one that can quickly test forward DNS resolution is the command line tool, host. Open a terminal, and type in host name.domain.com. If the forward DNS record is properly set up, the return should be: host name.domain.com has address 111.222.333.444. Easy, right?

Testing reverse DNS

Next, test reverse DNS records. Reverse DNS is the process of taking an IP address, and resolving it to a domain name. As before, using the host command line tool is easiest. Open a terminal, and type in host 111.222.333.444. If the reverse DNS record is properly set up, the return should be: host 444.333.222.111.in-addr.arpa domain name pointer name.domain.com. It cannot be emphasized enough how important it is to have correctly configured forward and reverse DNS records. In particular, the Active Directory plug-in can be very sensitive to incorrect DNS configuration. Generally, if DNS is functioning correctly, binding to any Directory Service should be trivial. So, if DNS is working, what should be the next step?

Network problems

At times, testing DNS using host can point to the cause of Directory Service problems. However, it is very important to note that testing this is only testing servers providing the DNS records, not necessarily the resolution by the client machine.

The first, and most obvious way to test network connectivity is with the use of ping. Ping the server providing directory services, and determine whether the client has connectivity with the provider. Silly as it sounds, check the cable or IP address being provided by a wireless server. Often the simple things are the solution!

Next, using the tool lookupd, client side DNS resolution can be tested. Testing reverse DNS, using the interactive debug mode, can verify that the results returned by using host are what the client is using as well. Invoke the debugger with lookupd -d. Following the same testing procedure, first enter:

hostWithName: hostname.domain.com

Next, enter:

hostWithInternetAddress: 111.222.333.444

Both commands will return a lot of information, including the agent that is being used by the client, as well as cache information, and how many hits have occurred by the operating system. This information can point to subtle DNS problems if it is different from the information returned by the host command.

Authentication problems

If a machine is successfully bound, the next most common problem that is reported is the inability to authenticate to a directory service exhibited by a shaking login window. Let's tackle the simplest way to test authentication first.

Dirt

Dirt? Never heard of the tool? It is a lesser-known tool that can be used to test Directory Services from the command line. It is particularly useful when used to test authentication against a bound Directory Service. The syntax can be a little tricky, but when used, it can be quite powerful. The first test is to check that the user exists in the Directory Services node. Here's how, open a terminal and type:

dirt -u username -n

The return value should be:

User username was found in:
/DSNode

This test simply does a quick verification of the username that is being used to login, and makes sure that the OS X client can see the information contained by the Directory Node. Next, test user authentication using the node name as follows:

dirt -m "/Active Directory/All Domains" ¬
-u activedirectoryusername -p activedirectorypassword

The command above specifically tests Active Directory, but any valid domain node can be tested. Some important notes:

The -u flag uses the username from the node you are testing against, in the above example it is the Active Directory username

The -p flag uses the password from the username that is being tested. In the above example, it is the Active Directory account password

The node is the Search node as referenced in Directory Access. In the above example, all Active Directory domains are searched.

Local administrative privileges are not required to use this tool.

Currently, the password must be entered with the -p option, as omitting it does not work as documented in the manual page. The return value can provide very useful troubleshooting information. As an example, this output is returned with a bad password:

Call to dsGetRecordList returned count = 1 with Status : eDSNoErr : (0)
Username: username
Password: password
Error : eDSAuthFailed : (-14090)

This return status very clearly reflects the failed password authentication. Let's dive even deeper.

Kerberos

Kerberos is increasingly being used for authentication for many Directory Services. If the password is correct, but the shaking login window is still occurring, the next area to focus on, especially for Active Directory and Open Directory, is Kerberos troubleshooting. Fortunately, testing is painless using the command tool, kinit. Type in the following:

kinit username

On failure, a very understandable error message is displayed:

Kerberos Login Failed: Clock skew too big. 
Please check your time, time zone and daylight savings settings.

From this error message, it is clear that Kerberos is failing because the clock differential, referred to as skew, is too great. While many administrators set the clock to use a network timeserver, it is not uncommon for OS X to drift by more than five minutes; this is usually greater than the allowable clock skew. Adjust the date and time to be within five minutes of the Directory Services authentication source, and this problem is solved!

These problems are the 'low-hanging' fruit, and can usually quickly solve Directory Service problems. What about problems that are more difficult?

Bringing in the Big guns

What if none of these troubleshooting steps works? There are three ways to log information, one for Directory Services, one for Managed Client (MCX), and one for Portable Home Directories.

Directory Services

If none of the quick steps provides an answer, debugging Directory Services is often needed to troubleshoot particularly complex problems. There are two different levels of logging which can be invoked on demand USR1, and USR2. Both are turned on similarly, with the command:

killall -USR1 DirectoryService

USR1 will log information to

/Library/Logs/DirectoryService/DirectoryService.debug.log.

USR2 sends all information to the system.log file. One last thing, both levels can also be set by touching a file in the following directory as follows:

touch /Library/Preferences/DirectoryService/.DSLogDebugAtStart (USR1)
touch /Library/Preferences/DirectoryService/.DSLogAPIAtStart (USR2)

Reboot the client, and debugging will begin at boot time.

Managed Client Services (MCX)

Debugging information can be collected and set using a command line only option:

defaults write /Library/Preferences/com.apple.MCXDebug debugOutput 3

Writing this preference will log all information relating to client management to the system.log file. Three is the maximum value that can be set. Using this value, a tremendous amount of information can be seen in the client log, and may point to managed client problems.

Portable Home Directories

Portable home directories can also be logged with a hidden preference:

defaults write com.apple.MirrorAgent debugOutput 4

This preference will log all portable home directory information to ~/Library/Logs/MirrorAgent.log. Again, though not fun, this information can often point to the source of trouble when attempting to diagnose a sticky Portable Home Directory problem.

Conclusion

Diagnosing and troubleshooting can be one of the most complex issues in the integration of OS X clients into heterogeneous network infrastructures. Remember to always start from the simplest explanation, as it often is the source of the problem. It is easy to errantly assume a much larger problem, when, in fact, the problem may be quite simple. However, with the above techniques and tools, bending Directory Services to your will should be far simpler.


Philip Rinehart is co-chair of the steering committee leading the Mac OS X Enterprise Project (macenterprise.org) and is the Lead Mac Analyst at Yale University. He has been using Macintosh Computers since the days of the Macintosh SE, and Mac OS X since its Developer Preview Release. Before coming to Yale, he worked as a Unix system administrator for a dot-com company. He can be reached at: philip.rinehart@yale.edu.

The MacEnterprise project is a community of IT professionals sharing information and solutions to support Macs in an enterprise. We collaborate on the deployment, management, and integration of Mac OS X client and server computers into multi-platform computing environments

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

1Password 5.1 - Powerful password manage...
1Password is a password manager that uniquely brings you both security and convenience. It is the only program that provides anti-phishing protection and goes beyond password management by adding Web... Read more
GarageSale 6.9.2 - Create outstanding eB...
GarageSale is a slick, full-featured client application for the eBay online auction system. Create and manage your auctions with ease. With GarageSale, you can create, edit, track, and manage... Read more
calibre 2.17 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital librarian... Read more
OmniGraffle Pro 6.1.2 - Create diagrams,...
OmniGraffle Pro helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use... Read more
OmniGraffle 6.1.2 - Create diagrams, flo...
OmniGraffle helps you draw beautiful diagrams, family trees, flow charts, org charts, layouts, and (mathematically speaking) any other directed or non-directed graphs. We've had people use Graffle to... Read more
RoboForm 2.0.2 - Password manager; syncs...
RoboForm is a password manager that offers one-click login, mobile syncing, easy form filling, and reliable security. Password Manager. RoboForm remembers your passwords so you don't have to! Just... Read more
Apple MainStage 3.1 - Live performance t...
Love the sound you got on your recording? MainStage 3 makes it easy to bring all the same instruments and effects to the stage. Everything from the Sound Library and Smart Controls you're familiar... Read more
Freeway Pro 7.0.2 - Drag-and-drop Web de...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With its user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
A Better Finder Rename 9.44 - File, phot...
A Better Finder Rename is the most complete renaming solution available on the market today. That's why, since 1996, tens of thousands of hobbyists, professionals and businesses depend on A Better... Read more
Stacks 2.6.9 - New way to create pages i...
Stacks is a new way to create pages in RapidWeaver. It's a plugin designed to combine drag-and-drop simplicity with the power of fluid layout. Features: Fluid Layout: Stacks lets you build pages... Read more

This Week at 148Apps: January 19-23, 201...
Warm Your Winter With New Apps!   How do you know what apps are worth your time and money? Just look to the review team at 148Apps. We sort through the chaos and find the apps you’re looking for. The ones we love become Editor’s Choice, standing out... | Read more »
Eggmaster Review
Eggmaster Review By Jennifer Allen on January 26th, 2015 Our Rating: :: BRIEFLY COMPELLINGUniversal App - Designed for iPhone and iPad Tap like crazy to gain eggs, so that you can buy upgrades to gain more eggs, and so on. It... | Read more »
Cloudy Or Dry – Funny Or Die Release a W...
Cloudy Or Dry – Funny Or Die Release a Weather App Posted by Ellis Spice on January 26th, 2015 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
Mediocre, the Team Behind Smash Hit, is...
Mediocre, the Team Behind Smash Hit, is Teasing Their Latest Unnamed Project Posted by Jessica Fisher on January 26th, 2015 [ permalink ] | Read more »
Heroes of Gaia Review
Heroes of Gaia Review By Campbell Bird on January 26th, 2015 Our Rating: :: TIMERS OF MIGHT AND MAGICUniversal App - Designed for iPhone and iPad This free-to-play rpg looks a lot like Heroes of Might and Magic, but it’s poor... | Read more »
Choice Provisions is Set to Launch Destr...
Choice Provisions is Set to Launch Destructamundo on iOS This Month Posted by Tre Lawrence on January 23rd, 2015 [ permalink ] Choice Provisions – home stable to | Read more »
King of Thieves – An Interview With Zept...
Ahead of the release of ZeptoLab’s King of Thieves, we were able to ask ZeptoLab’s co-founder, Semyon Voinov, a few questions about the inspiration behind the game and what that means for the Cut the Rope franchise. | Read more »
Handle Review
Handle Review By Jennifer Allen on January 23rd, 2015 Our Rating: :: SPEEDY ORGANIZINGUniversal App - Designed for iPhone and iPad Handle is a very convenient way of juggling your emails, To Do list, and Calendar all through one... | Read more »
The New Disney Inquizitive App Offers a...
The New Disney Inquizitive App Offers a Place for Fans to Take Disney Quizzes Posted by Tre Lawrence on January 23rd, 2015 [ permalink ] | Read more »
Hands-On With Cut the Rope Developer Zep...
Marking quite a departure from ZeptoLab’s past successes, namely the Cut The Rope series, King of Thieves is shaping up to be quite promising. Due for release in February, we were lucky enough to have some time with a preview build to see exactly... | Read more »

Price Scanner via MacPrices.net

MasterCard Brings Contactless Payment, Apple...
MasterCard, the official card of the Waste Management Phoenix Open, and the PGA TOUR are bringing the latest payment technology to the spectator experience with the introduction of contactless... Read more
Petitioning Dropbox For Mac OS X 10.4 and 10....
Last week Dropbox announced to its users that app support for Mac OS X 10.4 and 10.5 will end May 18 — disappointing news for those of us who are still getting useful service out of older PPC Macs... Read more
Stop Street Harassment, Bullying, and Assault...
The STOP-ATTACK (http://www.stop-attack.com) app will leverage smartphone technology to make the world a safer place. Whether it’s bullying, street harassment or something even more sinister, the app... Read more
Stir Kinetic Desk M1 Standing Or Sitting Desk...
The age of the standing desk is upon us, and according to medical research, it’s arriving none too soon. The World Health Organization (WHO), reports that 60 to 85 percent of people worldwide lead... Read more
Bosch Opens North American eBike Conversion H...
Following its entry into the U.S. eBike market in early 2014, Bosch has established a new headquarters office for Bosch eBike Systems (http://www.bosch-ebike.us) in Southern California, expanding the... Read more
13-inch 2.4GHz Retina MacBook Pro (Apple refu...
The Apple Store has previous-generation Apple Certified Refurbished 13″ 2.4GHz/128GB Retina MacBook Pros available for $999. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.4GHz/... Read more
13-inch 2.6GHz Retina MacBook Pro on sale for...
Adorama has the 13″ 2.6GHz/128GB Retina MacBook Pro on sale for $1189.99, $110 off MSRP. Shipping is free, and Adorama charges NY & NJ sales tax only. Read more
College Student Deals are back, additional $5...
Take an additional $50 off all MacBooks and iMacs at Best Buy Online with their College Students Deals Savings, valid through April 11, 2015. Anyone with a valid .EDU email address can take advantage... Read more
iPhone 6 and 6 Plus GIve Apple Half Of US Mob...
Chicago-based Consumer Intelligence Research Partners, LLC (CIRP) have released analysis of the results of its research on mobile phone manufacturers for the calendar quarter that ended December 31,... Read more
Save $100 on MacBook Airs with 256GB of stora...
B&H Photo has 256GB MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 1.4GHz/256GB MacBook Air: $999 $100 off MSRP - 13″ 1.4GHz/256GB MacBook... Read more

Jobs Board

Detailer *Apple* Ford Body Shop / Collision...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive , Read more
*Apple* Acura/Subaru Service Technicians - A...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive , Read more
Business Development Manager - *Apple* Pay...
**Job Summary** Apple Pay is seeking an experienced business development manager to support the identification, recruitment, negotiation and ongoing management of Read more
*Apple* Solutions Consultant (ASC)- Retail S...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.