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Collect Centrify DirectControl Debug Log

In this post I am gonna provide you the steps to collect the debug logs that should be provided while reporting an authentication failure issue with Centrify DirectControl. If you have the paid version then you can simply send an email to support@centrify.com with the logs files otherwise Centrify Forum is the one great stop shop for you. Make sure you run these steps before fixing the issue like restarting the system or restarting the centrifydc service.

These steps are for RHEL (Red Hat Enterprise Linux) users but other distributions should have similar steps just the directory structure might change a little bit,

Python Script: Check Ping Status and Lookup Hostname from IP List

Today I got a request to disable insecure SNMP v1 / v2c from a list of IP addresses. If you are still using SNMP v1 / v2c then it's really the time to disable the version and configure secured SNMP v3. Sometime ago I wrote a post on how to install and configure Net-SNMP v3 in Red Hat Enterprise Linux 4, you might wanna check that out as well. So, I had no idea what these servers are because I like to memorize my servers with their host name. And I didn't want to run nslookup or host or dig one by one on each IP. Also, I wanted to check whether these IP are alive / ping-able on my network or not. I could have used for loop and made one complicated command but for couple of reasons I chose not to do that,

adclient: DEBUG util.except (cims::RPC) : NetLogon::authenticate failed: Buffer Overflow

If you running DirectControl 5.0.x and have addebug enabled then you may see below authenticate failed messages pretty much every 30 seconds in your /var/log/centrifydc.log file,

adclient[12219]: DIAG  <bg:updateOS> smb.rpc.netlogon authenticate - useAuthen3=1.

adclient[12219]: DEBUG <bg:updateOS> util.except (cims::RPC) : NetLogon::authenticate failed: Buffer Overflow (reference ../smb/rpcclient/netlogon.cpp:247 rc: -2147483643)

These messages are getting logged because your computer's samAccountName (in layman's terms hostname) is greater than 15 characters long on DirectControl 5.0.x. This has been fixed in 5.1.0 and in current latest version that is 5.1.2 at the time of writing this blog post.

VMware vSphere: Design Workshop Class

It was the first day of my VMware vSphere: Design Workshop class and I was quite excited to learn the designing stuff, kind of my second step after VCP (VMware Certified Professionals) towards the vSphere Architect role. The class was taught by Patrick Fong trainer from www.ivtsys.com at VMware Singapore and I find him straight forward and nice guy. It’s a slides based training class and one of the good things about that is it covers most of the topics and details, big or small, that are necessary from the VMware’s perspective but it leaves less time to discuss the real life designs and the experiences. I want to see more production designs to talk about and little less theory as VMware has done a great job on white papers, documentation and knowledge base.

Setup Net-SNMP v3 on VMware ESX 4.0

Most enterprises have central monitoring system which is used to monitor pretty much every system/network gear in the infrastructure. In this post we will configure secure user based Net-SNMP v3 Agent on VMware ESX 4.0 so these hosts can also be monitored from the same central monitoring system in a secured manner. If you want to install and configured Net-SNMP v3 on RHEL4 systems then check out my other post. You need to perform these steps as root user so login to ESX 4.0 console as root now.

Bash Script: Monitor Inode Usage for UFS in Solaris 10

A file is the smallest unit of storage in the Unix file system (UFS). In Unix and Unix-like operating systems, each file is associated with an inode (Index Node) that stores the attributes like permissions, owner, group, size, type, time stamp, and etc. of file system objects like regular file, directory, and etc. Note that an inode contains all the information about a file except its name, which is kept in a directory. The size of an inode is 128 bytes. The inode allocation in UFS is static unlike XFS or NTFS that can easily cause lack of inodes if you have lot of small files. This makes the situation critical to place inode monitoring in place and do some trend analysis to prevent downtime. So here is a bash shell script to monitor the inode usage for UFS in Solaris 10. The script can send you the email notification if the inode usage goes over 90% and also logs the data in CSV format for tracking the growth. You need to run the script from cronjobs so that it can work even if you are not in front of your server.

Bash Script: List Last Modified Files on Linux Server

Today I am going to share a simple bash shell script to list the last modified files in a linux server directory. If I Google search this topic then I get several articles / blog posts suggesting to install some tools and then use that tool to find the information but I don't want to install anything on my server so I just went ahead and created one bash shell script that uses find command and placed it in my cronjob that notifies me via email if the content of the file(s) is changed or a new file is created in the directory.

Use SHRED over RM to Delete Sensitive Data in Linux

Are you looking for a way to securely delete the sensitive data (or files) from the hard drive in Linux? If yes, then this post is for you. I want to show you the shred command in Linux that overwrite the specified file(s) to hide and delete its contents. We are very much use to of using rm command in Linux to delete the files but in the background it just breaks the link (or unlink) the data block from its index number and the content of the file remains on the hard drive which can possibly be recovered using data recovery software or hardware appliances that makes rm command insufficient when it comes to destroy the data files. shred provides a mechanism to repeatedly overwrite the data file(s) and optionally delete it in order to make it harder for even very expensive hardware probing to recover the data.

Crontab: User not allowed to access to (crontab) because of pam configuration

Cron is a daemon in Linux that executes scheduled commands. Cron looks for /var/spool/cron directory for crontab files which are named after user accounts in /etc/passwd file and then found crontabs are loaded into the memory. Cron also searches for /etc/crontab file and the files in the /etc/cron.d directory. On Red Hat systems, crond supports access control with PAM (Pluggable Authentication Modules). A PAM configuration file for crond is installed in /etc/pam.d/crond. Crond loads the PAM environment from the pam_env module, but these can be overridden by settings in the crontab file.

Install and Configure Net-SNMP v3 on Red Hat Enterprise Linux 4

Today, we are going to install/update Net-SNMP on Red Hat Enterprise Linux 4. We will see how easy it is to disable the vulnerable SNMP v1/v2c and configure user based secure SNMP v3 Agent. You need to perform these steps as root user so login to the host as root now.

To install/update the Net-SNMP,

GoInstant, a New Addition in Salesforce family

GoInstant, Halifax, Nova Scotia based, possess the technological edge which complements the Salesforce.com. Hence, Salesforce has spent whopping 70 plus million dollars to fetch the deal so that they can amalgamate GoInstant to Salesforce. With the acquisition deal salesforce.com is looking forward to make the GoInstant team grow even better which is already known for incredibly sophisticated technology. There are more 1,00,000 subscribers which are supposed to be effective from this acquisition deal. This is going to be a delightful experience for the company to serve the customers in entirely new way. Though, GoInstant will remain continue delivering magnificent shared web experiences.

How to manage Information Security?

Admit it! These days all the organizations big or small are constantly struggling to find the effective mechanism to avoid security rift. In fact, they are cribbing for an effective mechanism to install information security so their data can be secure from virus attacks and hackers.  Hence, following blog post is my endeavor to high light some best possible solutions that I have learned through my experience.

Network Printer Configuration on Linux via Command Line

CUPS (formerly Common Unix Printing System) provides print server capabilities to Unix like Operating Systems. There are basically two components of CPUS: print spooler (or simultaneous peripheral output on line) and scheduler. CUPS is based on standard network protocol Internet Printing Protocol (IPP) for managing print jobs and queues. Most of the Linux distributions use CUPS as their default printing system including Red Hat starting with Red Hat Linux 9. Today we will complete network printer configuration on Red Hat Enterprise Linux 5 via command line using CUPS.

vCenter Server 5: Important Installation Tip

This is not a VMware certification exam question but it is good to know if you are working in production environment. I am assuming that you are already familiar with VMware vCenter Server but if not then you can always read the well prepared documentation by VMware.

When you run the VMware vCenter Installer you will see couple of pre-requisite for vCenter Server over right hand side, Microsoft .Net 3.5 SP1 and Windows Installer v4.5.