Unfortunately, setting logging to “ verbose” or “ trivia” didn’t add any additional useful information. Searching for a client-specific string to show we are using vCLI/ESXCLI is more difficult. Some good ones are “ rejected password for user”, the same “ LW_ERROR_PASSWORD_MISMATCH” as before and “ Cannot login”. Failed PowerCLI LoginĪgain, another target rich environment for strings regarding a failed login attempt using PowerCLI. You’ll see going forward, this isn’t used elsewhere. PowerCLI LoginĪ hint for figuring out if this is PowerCLI or not? Search for “ MS Web Services Client Protocol”. the “C#” client)?īecause we are connecting directly to ESXi servers in this blog article, we won’t be using the vSphere Web Client in any of these examples. What if I log in using the PowerShell or vCLI? Or the VI Client (a.k.a. That’s the system I SSH’d from) Client and API based logins Any of those will find you interesting login failure information, including where the login came from. You could search for “ LW_ERROR_PASSWORD_MISMATCH”, “ pam_sm_authenticate” or “ PAM: Authentication failure”. SSH login failures are also an excellent source for search strings. Some were the “ root” account logging in and later, an Active Directory login from SSH Failure You can see in the picture all the SSH sessions that have successfully logged in. In the case of SSH, we are looking for “ session opened” or “ session opened for user” SSH Login For SSH, the string is a little different. For logging in via the DCUI, the string we searched for was “ authentication of user”. It’s not just enough to log successful logins, but what about failed? As you can see from the image, there’s no shortage of strings to search for when it comes to failed DCUI logins! Looking for “DCUI” and “failed with authentication failure” should catch that straight away. In the latest login, you can now see that instead of “ root” logging in, it’s Failed DCUI Login Over the two days displayed I enabled Active Directory authentication on ESXi-02a. You’ll see in this example that I’m collecting from both ESXi servers. Here’s what that search looks like for all instances in my setup. In the image, I’m searching for “ DCUI” and “ root” but what you really should search for is “ authentication of user”. You’ll see the two events that you can search for. Note: Logs are displayed in descending order so read them from the bottom up DCUI Login What we’ll go into in more detail is the how.Īfter successfully logging in, let’s see what is in the syslog output. Note that all syslog output has a timestamp so the “when” part of the question is rather easy to answer. The first question is “When/How are my admin’s logging into ESXi?” Let’s take these use cases. Running logging set to trivia gives a lot of info, but really should only be used during a debugging process as it adds additional load on the host system and fills up your syslog receiver very quickly! When and How are administrators logging into ESXi In all my tests, I defaulted to using “ info” as the logging setting unless otherwise noted. If you are using vCenter+ESXi, using the configure-esx command in Log Insight is the way to go. You could use that script to modify your ESXi systems to send logs to the syslog receiver of your choice. If you are using standalone ESXi servers, Alan Renouf’s bulk ESXi host configuration script is a handy way to modify ESXi servers to send their logs to Log Insight. Normally, you wouldn’t run your ESXi systems this way, but for the purposes of the demonstration, I have them set up like that so I can show the different login messages from different authentication sources. I recall when the beta came out that someone posted that they had been using LI for a a couple of hours before they realized they hadn’t read the docs! (High praise indeed!!)ĮSXi server is configured with local authentication.ĮSXi server is configured with Active Directory authentication. As my colleague Alan Renouf said, “…one of the easiest and intuitive installers and configuration wizards ever!” Seriously, this virtual appliance is awesome. That is not to say you need or require Log Insight! You can use other syslog or SIEM (Security Incident and Event Management) tools. In this blog post I’ll use VMware’s new Log Insight tool. This blog post will show you how capturing and parsing ESXi’s syslog output can help you get this information.
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