Enumerating networks and building routes with PowerShell

I've been working with a company that is in the process of setting up a remote datacenter for disaster recovery. They brought me in to help design their Exchange cross-site resilience, and I've been helping them with a few other things too.

Primary connectivity between the primary datacenter and the remote datacenter is via an L2TP tunnel, nailed up and encrypted, across the public Internet, using RRAS.

With over 300 servers in the primary datacenter and over 100 servers targeted in the remote datacenter, we needed a way to set up the proper routes for each server farm to access the other (in both cases, the default gateway is a TMG array).

I decided that I could do that in a few lines of PowerShell. Truth be told, the basic functionality is pretty simple – you iterate through the computers you are examining, look at the wired network interfaces on those computers, see those that have a particular source IP address, and give them a route to the destination network.

However – and as always, the devil is in the details – It Ain't That Simple (IATS – HAH!).

First of all, Active Directory was used as the source of computers. That's great! However, there are computers in AD that aren't in DNS. I have no clue how that happened, but one can surmise that the computers were cut off, their IP addresses reassigned, and the computer object never removed from AD. That's one condition we have to deal with.

Secondly, as a corollary to the above, workgroup computers aren't found at all. With the solution presented here, there were already DNS entries for these computers (and there were only a handful of them), so we temporarily created computer objects for them in AD.

Third, we found some computers have bad IP addresses (specifically 0.0.0.0). Again, I have no clue how that happened, but those have to be filtered out.

Fourth, group policies in this organization aren't applied very logically. That's not what they called me in for, so I had little say. Regardless, a number of computer did not have remote management enabled, thus preventing remote examination of their configuration and remote changes to their configuration. Detection of computers without remote management thus became something the script had to deal with.

Fifth, we had first decided to use 'ping' to determine the accessibility of the computers as part of the discovery process. Well, fewer than half of the computers allowed 'ping' through their firewalls, so that solution had to be summarily discarded. In order to determine accessibility, we actually had to attempt to access the computers.

Sixth, and this is actually a downstream symptom of the issue above, on some servers remote management generates an error. Those servers need to be detected and repaired.

Seventh, and finally, some servers have multiple IP addresses. This may mean that they are already being used as RRAS servers and they need human intelligence to determine whether a route change should be applied.

I didn't use "route add" because in some situations "route add" is known to fail, and "netsh interface ipv4 add route" is preferred.

The resulting utility script is not particularly pretty. But it's very useful and the techniques illustrated are likely to be useful for you in your scripting needs too. So, I present it for your pleasure. 🙂


[string] $nl = "`r`n"

$HKCR = 2147483648
$HKCU = 2147483649
$HKLM = 2147483650

$script:badIP         = @()
$script:commands      = @()
$script:cannotping    = @()
$script:cannotresolve = @()
$script:cannotmanage  = @()
$script:warningmsg    = @()

function msg
{
	$str = ''

	foreach( $arg in $args )
	{
		$str += $arg + ' '
	}
	Write-Host $str
}

function RegRead
{
	Param(
		[string]$computer,
		[int64] $hive,
		[string]$keyName,
		[string]$valueName,
		[ref]   $value,
		[string]$type = "REG_SZ"
	)

	$wmi = [wmiclass]"\\$computer\root\default:StdRegProv"
	if( $wmi -eq $null )
	{
		$script:cannotmanage += $computer
		return 1
	}

	$r = $wmi.GetStringValue( $hive, $keyName, $valueName )
	$value.Value = $r.sValue

	$wmi = $null

	return $r.ReturnValue
}


function test-ping( [string]$server )
{
	[string]$routine = "test-ping:"

	trap 
	{
		# we should only get here if the New-Object fails.

		write-error "$routine Cannot create System.Net.NetworkInformation.Ping for $server."
		return $false
	}

	$ping = New-Object System.Net.NetworkInformation.Ping
	if( $ping )
	{
		trap [System.Management.Automation.MethodInvocationException] 
		{
			###write-error "$routine Invalid hostname specified (cannot resolve $server)."
			msg "...cannot resolve $server in DNS"
			$script:cannotresolve += $server
			return $false
		}

		for( $i = 1; $i -le 2; $i++ )
		{
			$rslt = $ping.Send( $server )
			if( $rslt -and ( $rslt.Status -eq [System.Net.NetworkInformation.IPStatus]::Success ) )
			{
				### msg "$routine Can ping $server. Successful on attempt $i."
				$ping = $null
				return $true
			}
			sleep -seconds 1
		}
		$ping = $null
	}

	###write-error "$routine Cannot ping $server. Failed after 5 attempts."
	msg "...cannot ping $server"
	$script:cannotping += $server

	return $false
}

### 
### Main
###

$start = (get-date).DateTime.ToString()
msg 'Begin' $start

ipmo ActiveDirectory
$computers = Get-AdComputer -Filter * -SearchBase "OU=Servers,DC=example,DC=com" -ResultSetSize $null | Select DnsHostName
msg "There are $($computers.Count) computers to check"
$computerCount = 0
foreach( $computer in $computers)
{
	$computerName = $computer.DnsHostName
	$computerCount++
	msg "Checking $computername... ($computerCount of $($computers.Count))"

#	if( -not ( test-ping $computerName ) )
#	{
#		###msg '...cannot resolve or ping'
#		msg ' '
#		continue
#	}

	### server IP addresses - I only care about IPv4
	$serverIPv4   = @()
	$serverIPname = @()

	$nicSettings = gwmi Win32_NetworkAdapterSetting -EA 0 -ComputerName $computerName
	if( $nicSettings -eq $null )
	{
		msg "...cannot access $computername"
		msg " "
		$script:cannotresolve += $computername
		continue
	}

	foreach( $nicSetting in $nicSettings )
	{
		### msg "Element=" $nicSetting.Element ## is of type Win32_NetworkAdapter
		if( $nicSetting.Element -eq $null )
		{
			msg "...netSetting.Element is null"
			continue
		}

		$nicElement = [wmi] $nicSetting.Element
		if( $nicElement -eq $null )
		{
			msg "...nicElement is null"
			continue
		}

		if( $nicElement.AdapterType -eq "Ethernet 802.3" )
		{
			### msg "Setting=" $nicSetting.Setting
			$nicConfig = [wmi] $nicSetting.Setting ## is of type Win32_NetworkAdapterConfiguration
			$nicGUID = $nicConfig.SettingID
			### msg "NicGUID=" $nicGUID
			### msg "NIC IPEnabled=" $nicConfig.IPEnabled.ToString()
			if( $nicConfig.IPEnabled -eq $true )
			{
				$returnValue = $true ## there is at least one valid NIC

				$hive = $HKLM
				$keyName = "System\CurrentControlSet\Control\Network\" +
					"{4D36E972-E325-11CE-BFC1-08002BE10318}\" + 
					$nicGUID + 
					"\Connection"
				$valueName = "Name"

				$name = ''
				$result = RegRead $computerName $hive $keyName $valueName ( [ref] $name ) 'reg_sz'
				if( $result -ne 0 )
				{
					$name = ""
				}

				###msg "NIC name:" $name

				$script:arrNicName += $name
				foreach( $ip in $nicConfig.IPAddress )
				{
					if( $ip.IndexOf( ':' ) -ge 0 )
					{
						$script:arrIPListPublic_v6 += $ip
						###msg "IPv6 address " $ip
					}
					else
					{
						$script:arrIPListPublic_v4 += $ip
						$serverIPv4   += $ip
						$serverIPname += $name
						###msg "IPv4 address:" $ip
					}
				}
			}
			$nicConfig = $null
		}
		$nicElement = $null
	}
	$nicSettings = $null

	$limit = $serverIPv4.Count - 1

	$allowedAddresses = 0
	for( $i = 0; $i -le $limit; $i++ )
	{
		$ip = $serverIPv4[ $i ]
		$name = $serverIPname[ $i ]

		if( $ip.Length -lt 10 )
		{
			$script:badIP += "$computerName $name $ip"
		}
		elseif( $ip.SubString( 0, 10 ) -eq "10.129.59." )
		{
			msg "*** YES - $computerName is on the server room secure network using NIC '$name' ***"
			$cmd = 'netsh -r ' + $computerName + 
				' interface ipv4 add route 10.129.68.0/22 "' + $name + '" 10.129.59.104'
			$script:commands += $cmd
			$allowedAddresses++
		}
		elseif( $ip.SubString( 0, 10 ) -eq "10.129.68." )
		{
			msg "*** YES - $computerName is on the datacenter network using NIC '$name' ***"
			$cmd = 'netsh -r ' + $computerName + 
				' interface ipv4 add route 10.129.59.0/20 "' + $name +'" 10.129.68.7'
			$script:commands += $cmd
			$allowedAddresses++
		}
	}
	if( $allowedaddresses -gt 1 )
	{
		msg "*** WARNING ***"
		$m = "$computerName has more than one IPv4 address. It may require extra configuration."
		msg $m
		$script:warningmsg += $m
		msg "*** WARNING ***"
	}

	if( $allowedaddresses -eq 0 )
	{
		msg "...no 10.129.59.0/24 or 10.129.68.0/24 IP addresses found on this computer (out of $($serverIPv4.Count))"
	}

	msg " "
}

msg "List of computers and NICs with bad IP addresses ($($script:badIP.Count))"
$script:badIP
' '

msg "List of computers in AD who cannot be accessed ($($script:cannotresolve.Count))"
$script:cannotresolve
' '

#msg "List of computers in AD who cannot be pinged ($($script:cannotping.Count))"
#$script:cannotping
#' '

msg "List of computer in AD who cannot be managed ($($script:cannotmanage.Count))"
$script:cannotmanage
' '

msg "Warning messages ($($script:warningmsg.Count))"
$script:warningmsg
' '

msg "Full list of routing commands ($($script:commands.Count))"
$script:commands
' '

msg 'Began at' $start
msg 'Done at' (get-date).DateTime.ToString()

 

Enumerating IP Addresses on Network Adapters using PowerShell

Regardless of whether a server is for Exchange, for SQL, or for any other use; a key component of the server’s configuration is the set of IP addresses assigned to it.

Many organizations apply all addresses (even server addresses) using DHCP. For servers, this is often based on reservations of the MAC addresses on those servers. In most cases, this works well. However, if the DHCP server(s) should be unavailable (for whatever reason), the server will not receive the desired address, and instead will receive an APIPA address (that is, an IPv4 address starting with “169.” as the first octet of the IPv4 address).

Regardless of the result, for many servers it is important to know if the IP addresses should change. The first step in that process is to be able to enumerate (list) all of the IP addresses for all of the network interfaces on the server.

There are a number of mechanisms available for obtaining this information from Windows; including but not limited to “ipconfig.exe”, WMI, “wmic.exe”, “netsh.exe”, and others. The challenge for using most of the available interfaces is that they provide a significant amount of extraneous information. Extraneous information makes the output very difficult to parse and use within scripts.

This blog post provides a script that enumerates all of the network interfaces available on a particular computer and the associated IP addresses. The second script, which you could schedule to run every 15-30 minutes, compares and contrasts any changes in IP addresses on a server and reports the change via a SMTP server (such as Exchange Server).

The first script:

 

###
### IP-Address-Check.ps1
###
### This script lists all Ethernet adapters supporting IP on a computer and
### the associated IP addresses - both IPv4 and IPv6. A simple object is
### output containing the name of the interface, an array containing the IPv4
### addresses, and an array containing the IPv6 addresses.
###
### While this information is available from netsh.exe, the format of the
### output from netsh.exe is not conducive for easy re-use or parsing.
###
### Michael B. Smith
### michael at smithcons dot com
### http://essential.exchange
### February 28, 2012
###

Set-StrictMode -Version 2.0

$HKLM = 2147483650
$wmi  = [wmiclass]"\root\default:StdRegProv"

function RegRead
{
	Param(
		[int64] $hive,
		[string]$keyName,
		[string]$valueName,
		[ref]   $value,
		[string]$type = "REG_SZ"
	)

	switch ( $type )
	{
		'reg_sz'
			{
				$r = $wmi.GetStringValue( $hive, $keyName, $valueName )
				$value.Value = $r.sValue
			}
		'reg_dword'
			{
				$r = $wmi.GetDWORDValue( $hive, $keyName, $valueName )
				$value.Value = $r.uValue
			}
		'reg_qword'
			{
				$r = $wmi.GetQWORDValue( $hive, $keyName, $valueName )
				$value.Value = $r.uValue
			}
		'reg_binary'
			{
				$r = $wmi.GetBinaryValue( $hive, $keyName, $valueName )
				$value.Value = $r.uValue
			}
		default
			{
				write-error "ERROR: RegRead $hive $keyName $valueName"
				return 1
			}
	}

	return $r.ReturnValue
}

function EnumerateAdapters
{
	$nicSettings = gwmi Win32_NetworkAdapterSetting -EA 0
	foreach( $nicSetting in $nicSettings )
	{
		$nicElement = [wmi] $nicSetting.Element
		if( $nicElement.AdapterType -eq "Ethernet 802.3" )
		{
			$nicConfig = [wmi] $nicSetting.Setting ## is of type Win32_NetworkAdapterConfiguration
			$nicGUID = $nicConfig.SettingID
			if( $nicConfig.IPEnabled -eq $true )
			{
				$hive = $HKLM
				$keyName = "System\CurrentControlSet\Control\Network\" +
					"{4D36E972-E325-11CE-BFC1-08002BE10318}\" + 
					$nicGUID + 
					"\Connection"
				$valueName = "Name"

				$name = ''
				$result = RegRead $hive $keyName $valueName ( [ref] $name ) 'reg_sz'
				if( $result -ne 0 )
				{
					$name = ""
				}

				$arrIPListPublic_v6 = @()
				$arrIPListPublic_v4 = @()

				foreach( $ip in $nicConfig.IPAddress )
				{
					if( $ip.IndexOf( ':' ) -ge 0 )
					{
						$arrIPListPublic_v6 += $ip
					}
					else
					{
						$arrIPListPublic_v4 += $ip
					}
				}

				$obj = "" | select Name, IPv4Addresses, IPv6Addresses
				$obj.Name = $name
				$obj.IPv4Addresses = $arrIPListPublic_v4
				$obj.IPv6Addresses = $arrIPListPublic_v6

				$obj  ### output the object to the pipeline

				$arrIPListPublic_v4 = $null
				$arrIPListPublic_v6 = $null
			}

			$nicConfig = $null
		}
		$nicElement = $null
	}
	$nicSettings = $null
}

###
### Main
###

EnumerateAdapters

 

The second script:

 

###
### IP-Check-Controller.ps1
###
### Check to see if any IP addresses on a computer have changed. This may 
### be relevant in many configurations based on DHCP.
###
### Michael B. Smith
### michael at smithcons dot com
### http://essential.exchange
### February 28, 2012
###

Param(
	[string]$to  = "ip-report@example.com",
	[string]$mx  = "mx.example.com",
	[string]$sub = "The IP address information has changed at $($env:ComputerName)",
	[string]$fr  = "ip-check-controller@example.local"
)

[string]$nl = "`r`n"

###
### Main
###

if( ( Test-Path "Addr-old.txt" -PathType Leaf ) )
{
	rm "Addr-old.txt"
}
if( ( Test-Path "Addr-new.txt" -PathType Leaf ) )
{
	mv "Addr-new.txt" "Addr-old.txt"
}

.\IP-Address-Check | out-file "Addr-new.txt"

$result = Compare-Object -ReferenceObject $(gc "Addr-old.txt") -DifferenceObject $(gc "Addr-new.txt") -PassThru
if( $result -eq $null )
{
	## no changes to file
	exit
}

### if we get here, the files are different

$text =
	"A change has occurred in the IP addresses or active adapters.$nl$nl"+
	"The changes found are:$nl"

foreach( $line in $result )
{
	$text += "`t" + $line + $nl
}

$text += $nl + "The new full configuration is:$nl"
	$lines = gc "Addr-New.txt"
	foreach( $line in $lines )
	{
		$text += "`t$line$nl"
	}

$text += $nl + "The old full configuration is:$nl"
	$lines = gc "Addr-Old.txt"
	foreach( $line in $lines )
	{
		$text += "`t$line$nl"
	}

Send-MailMessage -To $to -Subject $sub -From $fr -Body $text -SmtpServer $mx -Priority High

 

Typically, instead of scheduling the second PowerShell script, you would schedule a BAT script, as shown below:

 

@echo off
REM
REM IP-Check-Controller.bat
REM
REM Michael B. Smith
REM michael at smithcons dot com
REM http://essential.exchange
REM February 28, 2012
REM

powershell.exe -command ".\IP-Check-Controller.ps1"

 

Until next time…

If there are things you would like to see written about, please let me know.

 


Follow me on twitter: @EssentialExch

Sending an email to users whose password is about to expire, a PowerShell Rewrite

In September of 2005, I wrote a blog post named “Sending an e-mail to users whose password is about to expire“. Written in VBScript, it was one of my most popular blog posts of all time. I still have clients of mine that use it and I get occaisional email questions regarding it.

However, it is certainly showing its age!

There are other solutions available now, for free. However, the other solutions don’t meet all of my needs. (As always, I encourage you to choose the solution that best meets your needs.)

In my case, I need to be able to support:

  • Fast and efficient searching of Active Directory
  • Support for Fine Grained Password Policies (FGPPs, also known as Password Settings Objects or PSOs)
  • Authenticated SMTP
  • SSL/TLS SMTP
  • Report to Administrative User only (via SMTP)
  • Report to Administrative User only (via console)
  • Report to end-user (via SMTP)

The script in this blog post meets all of those needs. And, it is now written in PowerShell instead of VBScript.

I also chose to use the .Net Framework (System.DirectoryServices) for access to Active Directory (as well as some ADSI), instead of using the Active Directory PowerShell cmdlets. This makes it possible to execute the script on pretty-much any domain-joined computer, instead of one that requires RSAT-ADDS to be installed. It also avoids some weirdness around certain values returned by the AD cmdlets not matching older cmdlets or the AD itself.

This script is designed to work with PowerShell v2.0. The only PowerShell v2.0 feature is use of the Send-MailMessage cmdlet and using splatting to call Send-MailMessage. If you need this on PowerShell v1.0, you must just write a replacement for Send-MailMessage (use System.Net.Mail – it’s not a big deal).

The script will work on any domain functional level (DFL). The DFL is relevant to whether Fine-Grained Password Policies (FGPP, also known as Password Settings Objects – PSOs) are in use or not. FGPPs can be used when the domain level is at Windows 2008 or higher.

Coming in at 767 lines, this is the longest single PowerShell script I believe I’ve posted. But it’s well documented and hopefully self-descriptive. There are some fairly advanced capabilities demonstrated in this script, so you may find it worthwhile to study it a bit. If you have questions, let me know.

###
### Send-MailToUsersWithExpiringPasswords
###
### The top third of the script is data acquisition (and well documented).
### The bottom two-thirds is simple email-sending and report writing.
###
### This is PowerShell v1 compatible EXCEPT for using Send-MailMessage. You can
### easily replace that using System.Net.Mail if you wish.
###
### Parameter information:
###	daysForEmail   - how many days before a password expires should a user receive warning emails
###	adminEmail     - the administrator's email address
###	adminEmailOnly - do not send email to users, only report to the administrator
###	SMTPfrom       - the From address for the SMTP message(s)
###	SMTPserver     - the server to be used for sending the SMTP message(s)
###	SMTPuser       - if credentials are required, the user for authenticating to the SMTP server
###	SMTPpassword   - if credentials are required, the password for the SMTPuser
###	anr            - instead of searching all users, only search for users matching the specified ANR string
###	SMTPuseSSL     - use an SSL/TLS connection, not a clear-text SMTP connection
###	Quiet          - if NOT set, a copy of the admin report is dumped to the pipeline as text
###	DontSendEmail  - Email is never sent to either users or admin
###

Param(
	[int]$daysForEmail = 14,
	[string]$adminEmail = "michael@smithcons.com",
	[switch]$adminEmailOnly,
	[string]$SMTPfrom,
	[string]$SMTPserver,
	[string]$SMTPuser,
	[string]$SMTPpassword,
	[string]$anr,
	[switch]$SMTPuseSSL,
	[switch]$Quiet,
	[switch]$DontSendEmail
)

### Using Set-StrictMode helps protect against wonky errors that get caught by the
### compiler in compiled languages. Specifically (from the helpfile for the cmdlet):
### -- Prohibits references to uninitialized variables (including uninitialized 
###    variables in strings).
### -- Prohibits references to non-existent properties of an object.
### -- Prohibits function calls that use the syntax for calling methods.
### -- Prohibits a variable without a name (${}).
###
### However, using strict mode means that extra care has to be taken when using
### hashtables and property value collections. You see that in this script every
### time you see the Item() accessor method being used.

Set-StrictMode -Version 2.0

### For information about ANR, see "Ambiguous Name Resolution" in
### http://technet.microsoft.com/en-us/library/cc978014.aspx

$domainObject = [System.DirectoryServices.ActiveDirectory.Domain]::GetCurrentDomain()
$domainName   = $domainObject.Name
$domainRoot   = "LDAP://" + $domainName
$domainADSI   = [ADSI]$domainRoot
$domainMode   = $domainADSI.'msDS-Behavior-Version' ## Windows2008Domain is 3.

### domainMode is a PITA. System.DirectoryServices.ActiveDirectory.Domain.DomainMode and
### Microsoft.ActiveDirectory.Management.ADDomainMode have different values for the same
### enums!
###
### The first type is returned by System.DirectoryServices, the second type by the
### Get-ADDomain PowerShell cmdlet.
###
### That is why I ignore both of those potential access methods and use ADSI to access the
### value directly from the domain object. For specific information about those values, see:
### http://msdn.microsoft.com/en-us/library/cc223742(v=prot.10).aspx

[System.Int64]$Script:MaxPasswordAge = 0

function GetMaximumPasswordAge
{
	###
	### GetMaximumPasswordAge
	###
	### Retrieve the maximum password age that is set on the domain object. This is
	### normally set by the "Default Domain Policy".
	###

	if( $Script:MaxPasswordAge )
	{
		### Cache the value so that it only has to be retrieved once, converted
		### to an int64 once, and converted to days once. Win-win-win.

		return $Script:MaxPasswordAge
	}

	### Dealing with ADSI unfortunately also means dealing with COM objects.
	### Using ConvertLargeIntegerToInt64 takes the COM object and converts 
	### it into a native .Net type.

	[System.Int64]$Script:MaxPasswordAge = $domainADSI.ConvertLargeIntegerToInt64( $domainADSI.maxPwdAge.Value )

	### Convert to days
	### 	there are 86,400 seconds per day (24 * 60 * 60)
	### 	there are 10,000,000 nanoseconds per second

	[System.Int64]$Script:MaxPasswordAge = ( -$Script:MaxPasswordAge / ( 86400 * 10000000 ) )

	return [System.Int64]$Script:MaxPasswordAge
}

function newSecurePassword( [string]$password )
{
	###
	### newSecurePassword
	###
	### Take the normal string password provided and turn it into a 
	### secure string that can be used to set credentials.
	###
	### In PowerShell v2.0, this can be done with ConvertTo-SecureString.
	### That cmdlet isn't available in v1.0 though.
	###

	$secure = New-Object System.Security.SecureString

	$password.ToCharArray() |% { $secure.AppendChar( $_ ) }

	return $secure
}

function newPSCredential( [string]$username, [string]$password )
{
	###
	### newPSCredential
	###
	### Create a new PSCredential object containing the provided
	### username and plain-text password.
	###

	$pass = newSecurePassword $password

	$cred = New-Object System.Management.Automation.PSCredential( $username, $pass )
	$pass = $null

	return $cred
}

###
### We need to find all those user's who:
###	Are normal users                       0x00000200 ADS_UF_NORMAL_ACCOUNT
###	Are not disabled                       0x00000002 ADS_UF_ACCOUNTDISABLE
###	Do not have "password never expires"   0x00010000 ADS_UF_DONT_EXPIRE_PASSWD
###	Do not have "no password required"     0x00000020 ADS_UF_PASSWD_NOTREQD
###
###	Once we have the users, determine whether the user has a PSO
###	by examining msDS-PSOApplied (if the domain mode of the executing domain
###	is at Windows2008Domain or higher).
###
###	If the user has a PSO, load the PSO (and store it to a hashtable)
###	and evaluate the user's password against the PSO.
###
###	If the user does not have a PSO, evalute the user's password
###	against the Default Domain Policy Maximum Password Age (which
###	is found by the function GetMaximumPasswordAge above).
###
### The most efficient way to find users is to do an LDAP search. But building the
### proper search isn't that easy. We need a number of filters:
###
###	objectCategory=Person
###	(userAccountControl & ADS_UF_NORMAL_ACCOUNT)     <> 0
###	(userAccountControl & ADS_UF_ACCOUNTDISABLE)     == 0
###	(userAccountControl & ADS_UF_DONT_EXPIRE_PASSWD) == 0
###	(userAccountControl & ADS_UF_PASSWD_NOTREQD)     == 0
###
### Since userAccountControl is a BIT-FLAG attribute (meaning that individuals bits
### of the value control these options) then we need to be able to do a bit-wise
### LDAP search. It's important to realize that with a bit-wise search, the result
### of a particular filter is either not-one (!1, which is false) or not-zero (!0,
### which is true).
###
### So the next step in building our query is to use the LDAP bit-wise AND filter:
###
###	1.2.840.113556.1.4.803
###
### This is used to do a bit-wise AND of the attribute on the left to the value
### on the right. For example:
###
###	attribute:1.2.840.113556.1.4.803:=1024
###
### This means a bit-wise AND is done of the value of the attribute to the value
### 1024 (which is 0x400 in hexadecimal). If the result of that bit-wise AND is
### zero, then the value of the filter is false. If the result is non-zero, then
### the value of the filter is true. Putting a "!" in front of a false result
### makes the result true. Putting a "!" in front of a true result, makes it false.
###
### A combination of these two techniques makes it possible to scan for zero and
### non-zero bits (that is, those which are set to one and those which are set to
### zero).
###
### LDAP also supports a bit-wise OR filter, using the special value of:
###
###	1.2.840.113556.1.4.804
###
### Given the presence of AND and OR filters, it is possible to build very complex
### combination filters.
###
### A combination filter is built up of individual filters combined with either a
### logical OR ("|") or a logical AND ("&") and surrounded by parentheses.
###
###	(&
###		(objectCategory=Person)
###		(userAccountControl:1.2.840.113556.1.4.803:=512)
###		(!userAccountControl:1.2.840.113556.1.4.803:=2)
###		(!userAccountControl:1.2.840.113556.1.4.803:=65536)
###		(!userAccountControl:1.2.840.113556.1.4.803:=32)
###	)
###
### So, in pseudo-C code this is:
###
###	if( ( objectCategory == Person ) AND
###	    ( ( userAccountControl & ADS_UF_NORMAL_ACCOUNT     ) != 0 ) AND
###	    ( ( userAccountControl & ADS_UF_ACCOUNTDISABLE     ) == 0 ) AND
###	    ( ( userAccountControl & ADS_UF_DONT_EXPIRE_PASSWD ) == 0 ) AND
###	    ( ( userAccountControl & ADS_UF_PASSWD_NOTREQD     ) == 0 ) )
###	{
###		### we've got a matching user!
###	}
###
$ldapFilter =   "(&"							      +
			"(objectCategory=Person)"                             +
			"(userAccountControl:1.2.840.113556.1.4.803:=512)"    +
			"(!userAccountControl:1.2.840.113556.1.4.803:=2)"     +
			"(!userAccountControl:1.2.840.113556.1.4.803:=65536)" +
			"(!userAccountControl:1.2.840.113556.1.4.803:=32)"

if( $anr )
{
	###
	### using an ANR subquery allows us to reduce the result set from the LDAP query
	###
	$ldapFilter += "(anr=$anr)"
}

$ldapFilter += ")"

###
### build the LDAP search
###

$directorySearcher = New-Object System.DirectoryServices.DirectorySearcher
$directorySearcher.PageSize    = 1000
$directorySearcher.SearchRoot  = $domainRoot
$directorySearcher.SearchScope = "subtree"
$directorySearcher.Filter      = $ldapFilter

###
### load the properties we want
###

$directorySearcher.PropertiesToLoad.Add( "displayName"        ) | Out-Null
$directorySearcher.PropertiesToLoad.Add( "mail"               ) | Out-Null
$directorySearcher.PropertiesToLoad.Add( "pwdLastSet"         ) | Out-Null
$directorySearcher.PropertiesToLoad.Add( "sAMAccountName"     ) | Out-Null
$directorySearcher.PropertiesToLoad.Add( "userAccountControl" ) | Out-Null

if( $domainMode -ge 3 )
{
	### this attribute is only valid on Windows2008Domain and above
	$directorySearcher.PropertiesToLoad.Add( "msDS-PSOApplied" ) | Out-Null
}

$users = $directorySearcher.FindAll()

###
### All the data is in $users (or will be paged into $users).
### Build the necessary reports and emails.
###

$crnl = "`r`n"
$script:adminReport = ""

function line
{
	foreach( $arg in $args )
	{
		$script:adminReport += $arg + $crnl
	}
}

$now = Get-Date
$maximumPasswordAge = GetMaximumPasswordAge

line ( "Admin Report - Send Mail to Users with Expiring Passwords - Run Date/Time: " + $now.ToString() )
line " "
line "Parameters:"
line "        Days warning for sending email: $daysForEmail"
line "        Administrator email: $adminEmail"

if( $DontSendEmail )
{
	line "        Email will not be sent to either the administrator email or to user's email"
}
elseif( $adminEmailOnly )
{
	line "        Only the administrator will be sent email"
}

if( ![System.String]::IsNullOrEmpty( $SMTPfrom ) )
{
	line "        SMTP From address: $SMTPfrom"
}

if( ![System.String]::IsNullOrEmpty( $SMTPserver ) )
{
	line "        SMTP server: $SMTPserver"
}

if( ![System.String]::IsNullOrEmpty( $SMTPuser ) )
{
	line "        SMTP user: $SMTPuser"
}

if( ![System.String]::IsNullOrEmpty( $SMTPpassword ) )
{
	line "        SMTP password: $SMTPpassword"
}

if( $SMTPuseSSL )
{
	line "        UseSSL with SMTP is set"
}

line "        Maximum Password Age in Default Domain Policy = $maximumPasswordAge"
line "        Domain Mode $($domainObject.DomainMode.ToString())"
line ( "        User count = " + $users.Count.ToString() )

if( [System.String]::IsNullOrEmpty( $SMTPserver ) -and [System.String]::IsNullOrEmpty( $PSEmailServer ) -and !$DontSendEmail )
{
	Write-Error "No email server was specified via the SMTPserver parameter or the `$PSEmailServer environment variable."
	exit
}

if( ![System.String]::IsNullOrEmpty( $SMTPuser ) -and [System.String]::IsNullOrEmpty( $SMTPpassword ) )
{
	Write-Error "No SMTPpassword was specified."
	exit
}

if( ![System.String]::IsNullOrEmpty( $SMTPpassword ) -and [System.String]::IsNullOrEmpty( $SMTPuser ) )
{
	Write-Error "No SMTPuser was specified."
	exit
}

if( [System.String]::IsNullOrEmpty( $SMTPfrom ) )
{
	$SMTPfrom = "Password Administrator "
}

###
### some of the bitflags attached to the userAccountControl attribute
###

$ADS_UF_NORMAL_ACCOUNT     = 0x00200
$ADS_UF_ACCOUNTDISABLE     = 0x00002
$ADS_UF_DONT_EXPIRE_PASSWD = 0x10000
$ADS_UF_PASSWD_NOTREQD     = 0x00020

$psoCache = @{}

foreach( $user in $users )
{
	###
	### we spend some time being pretty careful dealing with the properties. this
	### allows us to verify we get the attributes we want, and for those that were
	### not present, we can establish reasonable defaults.
	###

	line " "

	$propertyBag = $user.properties
	if( !$propertybag )
	{
		line "error! null propertybag!"
		continue
	}

	$mail = ""
	$disp = ""
	$sam  = ""
	$pls  = 0
	$pso  = 0
	$uac  = 0
	$pwdX = $null

	$dispObj = $propertyBag.Item( 'displayname' )
	if( $dispObj -and ( $dispObj.Count -gt 0 ) )
	{
		$disp = $dispObj.Item( 0 )
		if( !$disp ) { $disp = "" }
	}
	$dispObj = $null
	### line "displayname = $disp"

	$samObj = $propertyBag.Item( 'samaccountname' )
	if( $samObj -and ( $samObj.Count -gt 0 ) )
	{
		$sam = $samObj.Item( 0 )
		if( !$sam ) { $sam = "" }
	}
	else
	{
		$sam = ""
	}
	$samObj = $null
	### line "sam = $sam"

	$uacObj = $propertyBag.Item( 'useraccountcontrol' )
	if( $uacObj -and ( $uacObj.Count -gt 0 ) )
	{
		$uac = $uacObj.Item( 0 )
	}
	else
	{
		line "no uac for $sam, assumed 0x200"
		$uac = $ADS_UF_NORMAL_ACCOUNT
	}
	$uacObj = $null
	### line "uac = $uac"

	$plsObj = $propertyBag.Item( 'pwdlastset' )
	if( $plsObj -and ( $plsObj.Count -gt 0 ) )
	{
		$pls = $plsObj.Item( 0 )
	}
	else
	{
		### this can be a normal occurence if the password has never been set
		$pls = 0
	}
	$plsObj = $null
	### line "pls = $pls"

	line ( $sam.PadRight( 21 ) + $pls.ToString().PadRight( 21 ) + $uac.ToString().PadRight( 8 ) + '0x' + $uac.ToString('x').PadRight( 8 ) )

	if( $pls -eq 0 )
	{
		line ( " " * 8 + "The password has never been set for this user, skipped" )
		continue
	}

	[System.Int64]$localMaxAge = $maximumPasswordAge

	if( $domainMode -ge 3 )
	{
		###
		### PSOs can be created on Server 2003, but they don't work properly until
		### the domain mode is Windows2008Domain or higher.
		###
		### So if we find a PSO and the domain mode is Windows2008Domain or higher,
		### we first determine whether we've seen this PSO before. If we have seen
		### the PSO before, then we've stored the msDS-MaximumPasswordAge value for
		### the PSO into a hash table for quick retrieval. If we have not seen the
		### PSO before, then we use ADSI to load the PSO and retrieve the value for
		### msDS-MaximumPasswordAge and then cache the value for future access. By
		### using a cache, we only have to access Active Directory to obtain values
		### once per PSO, leading to a significant performance improvement compared
		### to using the native cmdlets or S.DS.
		###

		$psoObj = $propertyBag.Item( 'msds-psoapplied' )
		if( $psoObj -and ( $psoObj.Count -gt 0 ) )
		{
			$pso = $psoObj.Item( 0 )
			### line ( "PSO object/name" + $pso )

			if( $psoCache.Item( $pso ) )
			{
				[System.Int64]$localMaxAge = $psoCache.Item( $pso )
				### line ( " " * 8 + "Accessed PSO from cache = " + $pso )
			}
			else
			{
				$psoADSI = [ADSI]( "LDAP://" + $pso )
				$ageOBJ = $psoADSI.'msDS-MaximumPasswordAge'

				[System.Int64]$localMaxAge = $psoADSI.ConvertLargeIntegerToInt64( $ageOBJ.Value )

				### Convert to days
				### 	there are 86,400 seconds per day (24 * 60 * 60)
				### 	there are 10,000,000 nanoseconds per second
				$localMaxAge = ( -$localMaxAge / ( 86400 * 10000000 ) )

				$psoCache.$pso = $localMaxAge
				### line ( " " * 8 + "Stored PSO to cache = " + $pso )

				$ageOBJ  = $null
				$psoADSI = $null

				### line "localMaxAge = $localMaxAge"
			}
		}
		else
		{
			### completely normal to not have a PSO, in that case, use the maxPwdAge
			### from the default domain policy.
			$pso = $null
			### line "pso is null"
		}
		$psoObj = $null
	}

	### In an Exchange environment, the 'mail' attribute contains the primary SMTP
	### address for a user. In a non-Exchange environment, that should also be true,
	### but no system process validates it. We do presume that the mail address is
	### valid, if present.

	$mailObj = $propertyBag.Item( 'mail' )
	if( $mailObj -and ( $mailObj.Count -gt 0 ) )
	{
		$mail = $mailObj.Item( 0 )
	}
	else
	{
		$mail = ''
	}

	if( 0 )
	{
		### The conditions reported on below cannot occur based on our LDAP filter
		### But they helped me develop and test the LDAP filter. :-)

		if( $uac -band $ADS_UF_NORMAL_ACCOUNT )
		{
			"`t`tNormal account"
		}
		else
		{
			"`t`tNot a normal account"
		}
		if( $uac -band $ADS_UF_ACCOUNTDISABLE )
		{
			"`t`tAccount disabled"
		}
		else
		{
			"`t`tAccount enabled"
		}
		if( $uac -band $ADS_UF_DONT_EXPIRE_PASSWD )
		{
			"`t`tPassword doesn't expire"
		}
		else
		{
			"`t`tPassword expires"
		}
		if( $uac -band $ADS_UF_PASSWD_NOTREQD )
		{
			"`t`tPassword not required"
		}
		else
		{
			"`t`tPassword required"
		}
	}

	### If we get here, $pls is non-zero.
	###
	### $pls comes to us in FileTime format (the number of 100 nansecond ticks 
	### since Jan 1, 1601). So it must be converted to DateTime and adjusted 
	### for the normal clock in order for us to do our arithmetic on it. For
	### more information about FileTime, see:
	### msdn.microsoft.com/en-us/library/windows/desktop/ms724290(v=vs.85).aspx

	$date = [DateTime]$pls
	$passwordLastSet = $date.AddYears( 1600 ).ToLocalTime()
	$passwordExpires = $passwordLastSet.AddDays( $localMaxAge )

	line ( " " * 8 + "The password was last set on " + $passwordLastSet.ToString() )

	if( $now -gt $passwordExpires )
	{
		line ( " " * 8 + "The password already expired on $($passwordExpires.ToString()). No email will be sent.")
		continue
	}
	else
	{
		line ( " " * 8 + "The password will expire on "  + $passwordExpires.ToString() )
	}

	$difference = $passwordExpires - $now
 	$days       = $difference.Days.ToString()
	$hours      = $difference.Hours.ToString()
	$minutes    = $difference.Minutes.ToString()

	line ( " " * 8 + "(This is in $days days, $hours hours, $minutes minutes)" )

	if( $difference.Days -le $daysForEmail )
	{
		if( [System.String]::IsNullOrEmpty( $mail ) -and !$adminEmailOnly )
		{
			line ( " " * 8 + "Oops - user doesn't have an email address." )
			continue
		}

		if( $DontSendEmail )
		{
			line ( " " * 8 + "Oops - we aren't supposed to send an email." )
			continue
		}

		line ( " " * 8 + "This user will be sent an email for password change." )

		$hash = @{}
		$hash.To       = $adminEmail
		$hash.Priority = 'High'
		$hash.From     = $SMTPfrom

		if( ![System.String]::IsNullOrEmpty( $disp ) )
		{
			$hash.Subject = "Warning! The network password for $disp ($sam) is about to expire."
		}
		else
		{
			$hash.Subject  = "Warning! The network password for $sam is about to expire."
		}

		if( !$adminEmailOnly -and ![System.String]::IsNullOrEmpty( $mail ) )
		{
			$hash.CC = $mail
		}

		if( ![System.String]::IsNullOrEmpty( $SMTPserver ) )
		{
			$hash.SmtpServer = $SMTPserver
		}
		elseif( ![System.String]::IsNullOrEmpty( $PSEmailServer ) )
		{
			$hash.SmtpServer = $PSEmailServer
		}

		###
		### Send-MailMessage will default to using $PSEmailServer when no other SMTP server is specified.
		### We checked earlier to ensure that at least one of those was specified.
		###

		if( ![System.String]::IsNullOrEmpty( $SMTPuser ) )
		{
			###
			### If SMTPuser is specified then SMTPpassword is also specified.
			### We checked earlier to make certain that if one was specified,
			### then both were specified.
			###

			$hash.Credential = newPSCredential $SMTPuser $SMTPpassword
		}

		if( $SMTPuseSSL )
		{
			$hash.UseSSL = $true
		}

		$bodyHeader = @"
WARNING!

"@
		$bodyHeader += "`r`nFor network user id: "
		if( ![System.String]::IsNullOrEmpty( $disp ) )
		{
			$bodyHeader += $disp + " (" + $sam + ")"
		}
		else
		{
			$bodyHeader += $sam
		}

		$hash.Body = @"
$bodyHeader

Your password is about to expire in $days days, $hours hours, $minutes minutes. 

Please change it now!

Thank you,
Your System Administrator
"@

		###
		### This is V2.0 function. I should replace it with something v1.0 compatible.
		### (splatting is also V2.0 only, which is why I'm lazy and didn't replace it.)
		###

		Send-MailMessage @hash

		$hash = $null
	}
}

###
### Invidual report emails complete.
### Now send summaries to the console and/or to the administrator email address.
###

line " "

if( !$quiet )
{
	###
	### If $quiet is NOT set, then dump the report to the console, as well
	### as sending the email to the administrator.
	###
	$script:adminReport
}

if( !$DontSendEmail )
{
	$hash = @{}
	$hash.To       = $adminEmail
	$hash.Priority = 'High'
	$hash.From     = $SMTPfrom
	$hash.Subject  = "Admin Report - Send Mail to Users with Expiring Passwords - Run Date/Time: " + $now.ToString()
	$hash.Body     = $adminReport

	###
	### Send-MailMessage will default to using $PSEmailServer when no other SMTP server is specified.
	### We checked earlier to ensure that at least one of those was specified.
	###

	if( ![System.String]::IsNullOrEmpty( $SMTPserver ) )
	{
		$hash.SmtpServer = $SMTPserver
	}
	elseif( ![System.String]::IsNullOrEmpty( $PSEmailServer ) )
	{
		$hash.SmtpServer = $PSEmailServer
	}

	if( ![System.String]::IsNullOrEmpty( $SMTPuser ) )
	{
		###
		### If SMTPuser is specified then SMTPpassword is also specified.
		### We checked earlier to make certain that if one was specified,
		### then both were specified.
		###

		$hash.Credential = newPSCredential $SMTPuser $SMTPpassword
	}

	if( $SMTPuseSSL )
	{
		$hash.UseSSL = $true
	}

	Send-MailMessage @hash

	$hash = $null
}

###
### Clean up a bit.
###

$now   = $null
$users = $null

$psoCache        = $null
$directorySearch = $null
$domainADSI      = $null
$domainObject    = $null

$script:adminreport = $null

### Done.

Until next time…

If there are things you would like to see written about, please let me know.


Follow me on twitter!  – @EssentialExch

Creating Explicit Credentials in PowerShell for WMI, Exchange, Lync, Remoting, etc.

When creating PowerShell cmdlets for any Microsoft technology – WMI, Exchange, Lync, etc. – it is common to need to provide credentials that are different from the default credentials. This can be even more important when you are using PowerShell remoting to connect to a remote computer.

However, using the built-in cmdlet Get-Credential causes a dialog box to be opened on the console! (And it will simply fail in some cases, when the internal PowerShell $host.UI.PromptForCredential interface has not been implemented.) This is certainly not something that you want to happen when your PowerShell script is being called with remote PowerShell or from a service, or in many other scenarios.

The solution is to pass in the full credential, already containing the secure password and the user names and (optionally) the domain or a user principal name. This is a bit challenging, as the constructor for a secure string doesn’t provide you an option for passing in an entire password. Therefore, you must build the secure string one character at a time.

The two functions below make the process easy.

Note: the $username parameter to newPSCredential can be in several formats: a plain username, a domain\username, or username@domain.com, or computername\username (for a local user).

Note 2: some functions want a NetworkCredential instead of a PSCredential. Creating one of those is as simple as changing System.Management.Automation.PSCredential to System.Net.NetworkCredential.

Note 3: as a security best practice, after you call the newPSCredential function, you should ensure that the plain text password is no longer available in the calling routine.

Enjoy!

function newSecurePassword( [string]$password )
{
        ###
        ### newSecurePassword
        ###
        ### Take the normal string password provided and turn it into a 
        ### secure string that can be used to set credentials.
        ###

        $secure = new-object System.Security.SecureString

        $password.ToCharArray() |% { $secure.AppendChar( $_ ) }

        return $secure
}

function newPSCredential( [string]$username, [string]$password )
{
	###
	### newPSCredential
	###
	### Create a new PSCredential object containing the provided
	### username and plain-text password.
	###
        $pass = newSecurePassword $password

        $cred = new-object System.Management.Automation.PSCredential( $username, $pass )

        $cred
}

 

Until next time…

If there are things you would like to see written about, please let me know.


Follow me on twitter! : @EssentialExch

Generating a report on Distribution Groups and their Membership, v2

In August of 2010, I posted Generating a report on Distribution Groups and their Membership. For most people, that script worked just fine.

However, it had some issues:

  • Large groups would cause PowerShell to generate an error about concurrent pipelines
  • The script generated string output instead of object output

This new version fixes those issues and adds ‘help’ content for the script. The script is below, but the information about the reasoning is copied directly from the original post, modified appropriately.

A common request is to get a list of all distribution groups and the members contained in that distribution group.

Note: a distribution group may also be a security group. From an Exchange Server perspective, the important thing is whether the group is mail-enabled or not.

You can take this report and pipe it to out-file in order to save the output to a disk file. Then you can inspect the file later, email it, copy-n-paste it, whatever you want. Export-Csv and Export-CliXml are also good options for exporting this data, especially since there is the potential for the contents of several arrays to be output.

Here is the script:

##
## Report-DistributionGroupsAndMembers.ps1
## v2.0
##
## Michael B. Smith
## http://TheEssentialExchange.com
## August, 2010
## July, 2011
##
## Requires the Exchange Management Shell
## As of version 2.0, requires PowerShell 2.0
## Tested on both Exchange 2007 and Exchange 2010
##

#requires -Version 2.0

if( $args )
{
	if( ( $args.Length -eq 1 ) -and
	    ( ( $args[0] -eq "-?" ) -or
	      ( $args[0] -eq "-help" ) ) )
	{
		@"

NAME
	Report-DistributionGroupsAndMembers

SYNOPSIS
	This script outputs information about all distribution groups. The 
	information includes:

	GroupName    - The name of the distribution group
	Identity     - The unique identity of the group (an X400 identifier)
	ManagerNames - An array containing the names of the managers for the
		group. On Exchange 2007, this will contain a maximum of one
		entry. On Exchange 2010, there may be many entries. It is
		also possible (and quite likely in some environments), for
		this array to be empty.
	ManagerCanonicalNames - An array containing the canonical names
		(also known as the relative distinguished name) for the
		managers of this group. It will match, index by index, the
		contents of ManagerNames.
	Members      - An array containing the names of all the members of
		this group. It is also possible for this array to be empty.

	This script must be executed from within an Exchange Management Shell. 

SYNTAX
	Report-DistributionGroupsAndMembers [-help]

"@ 		| out-default

		return
	}

	throw "No parameters are allowed for this script"
}

$distributionGroups = Get-DistributionGroup -ResultSize Unlimited

foreach( $distributionGroup in $distributionGroups )
{
	## not all of these temporaries are necessary, but it
	## simplifies understanding the PowerShell code

	$groupName  = $distributionGroup.Name
	$groupID    = $distributionGroup.Identity

	$managedBy  = $distributionGroup.ManagedBy
	$mgrName    = @()
	$mgrCName   = @()

	if( $managedBy -is [Microsoft.Exchange.Data.Directory.ADObjectId] )
	{
		$mgrName  += $managedBy.Name
		$mgrCName += $managedBy.RDN.ToString().SubString(3)
	}
	elseif( $managedBy.Count -gt 0 )
	{
		foreach( $manager in $managedBy ) 
		{
			$mgrName  += $manager.Name
			$mgrCName += $manager.RDN.ToString().SubString(3)
		}
	}

	$membersArray = @()

	$members = Get-DistributionGroupMember -Identity $groupID -ResultSize Unlimited
	foreach( $member in $members )
	{
		$membersArray += $member.Name
	}

	$members = $null

	$hash = @{
		GroupName		= $groupName
		Identity		= $groupID
		ManagerNames		= $mgrName
		ManagerCanonicalNames	= $mgrCName
		Members			= $membersArray
	}

	New-Object PSObject -Property $hash	## inject to the pipeline
}

$distributionGroups = $null

 

Until next time…

If there are things you would like to see written about, please let me know.


Follow me on twitter! : @EssentialExch

Black Hole Distribution Groups

I had the question posed to me today: if I have a mail-enabled group (either a security group or a distribution group) that has no members, and it receives an email, why don’t I get an NDR?

Well – works as intended!

Let’s have a thought experiment considering how mail-enabled groups work (from an Exchange perspective):

  1. Create a distribution group
  2. Assign it one or more email addresses
  3. Don’t add any members
  4. Send an email
  5. Let Transport expand the group
  6. For every member in the group, make a copy of the email
  7. Stop

What’s different about the empty group? Absolutely nothing. A copy of the email is made for every member of the group – it just so happens that there aren’t any members of the group!

Why would you do this? It’s commonly done for employees that have left a company. For some period of time, you may want an ex-employees supervisor or manager to receive their emails. But eventually, you just want them to “go away”.

It’s also commonly done for “temporary” email addresses. For example, your company decides to run a promotion, and your have your customers send an email to a custom temporary email address. When the promotion is done, black-hole the email.

Now, starting in Exchange 2007 you can also create custom responses with transport rules, if you need or want them.

Black hole distribution groups have worked this way since at least Exchange 5.5. A further note: it’s also common to hide these type of mail-enabled groups from the Exchange address book, so that they are not present in the GAL. Also be aware that you can have dozens of addresses assigned to a single group; so in most instances you’ll only need a single black hole distribution group in your organization.

Until next time…

As always, if there are items you would like me to talk about, please drop me a line and let me know!


Follow me on twitter! : @EssentialExch

Exchange 2003 FE Servers vs. Server 2008 Active Directory

I spent eight hours over the last two days figuring out an interesting – but weird – problem. Once I figured out the problem, correcting it was a simple matter.

I’ll just give you the problem description and then the solution. Hopefully it will save you more than a little time in the future.

I have a client (one of several in this particular situation) who has an Exchange 2003 Front-End server located in their DMZ. Yes, that’s right, their DMZ. In the “long-ago time”, this was considered to be a favored practice by Microsoft. That, of course, has changed over the years. Now, in 2011, we do not want any domain member servers located in the DMZ. Why is that? Because to install a domain member in a DMZ basically means that you have to make “swiss cheese” out of your firewall. And, effectively, if a DMZ server is compromised it means that your entire Active Directory can be compromised. The entire list of potentially affected ports is shown in KB 832017, and at the end of the day – it basically says that you have to open everything above port 1024 to make it all work.

With all that being said, if you are using Exchange 2003 with Server 2003 Active Directory (by which I mean an Active Directory domain controller hosted on a Windows Server 2003 server), you could get by with a much more limited set of ports (although it still isn’t small!):

DNS (TCP and UDP 53)
Kerberos (TCP and UDP 88)
RPC Endpoint Mapper (TCP 135)
NetBIOS Name Service (TCP 137)
NetBIOS Datagram Service (TCP 138)
NetBIOS Session Service (TCP 139)
LDAP (TCP and UDP 389)
Directory Services (TCP 445)
LDAP Global Catalog (TCP 3268)
Remote Desktop Protocol (TCP 3389)
Active Directory RPC End-Point (AD-RPC-EP)

You should notice that all of these have defined ports except for the last! By definition, the AD-RPC-EP is a random high port.

However, a somewhat surprising fact is that when you run Active Directory on Windows Server 2003 (in other words, you have a domain controller on Server 2003), the AD-RPC-EP is always either port 1025 or 1026!

Starting with Server 2008, this is no longer true. “Port randomization” ensures that ports are allocated at truly random locations.

So… I have a particular client who, as part of their Exchange 2003 to Exchange 2010 upgrade effort decided that they first wanted to upgrade their Active Directory. That was fine by me – there are no documented restrictions regarding the operating system level of domain controllers to be used by Exchange 2003.

The day we changed the last domain controller from Windows Server 2003 to Windows Server 2008 R2, the Exchange FE server stopped working. Oh, $%&#.

Thankfully, the FE server was only being used for Outlook Web Access (OWA). SMTP was injected into the Exchange environment via a Barracuda cluster directly into the internal back-end server environment.

I’m rather hardheaded. So I wanted to figure this out. And, quite frankly, it took awhile. Eventually, it took an examination using portqry and rpcping (you can find out lots of information about these utilities by using Google or Bing and searching for “portqry site:support.microsoft.com” and “rpcping site:support.microsoft.com”). Comparing the results of those to the “access control lists” from the firewall showed me that the firewall always expected a port to be open at TCP 1025 and/or TCP 1026. Neither of these ports were open on Server 2008 R2!

I went back and investigate some other customers who were running Active Directory on Server 2003. On every single one of their servers, the process lsass.exe had either TCP 1025 or TCP 1026 (or both) open.

A google here, a bing there, and I was led to Active Directory Replication Over Firewalls and KB 224196: Restricting Active Directory replication traffic and client RPC traffic to a specific port.

These led me to understand that on Server 2008 and above AD-RPC-EP could happen at any random port – but that there is a way to specify the port that will be used. YAY!

For the following

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters
Registry value: TCP/IP Port
Value type: REG_DWORD
Value data: (available port)

specifying a “value data” of either 1025 or 1026 ensures that Server 2008 and Server 2008 R2 operate as did Server 2003. After setting this value, it does take a reboot of the affected DC/server for the value to take effect.

Once this was done, my client was happy again! I hope this helps you in your migrations…

Until next time…

As always, if there are items you would like me to talk about, please drop me a line and let me know!


Follow me on twitter! : @EssentialExch

Finding Disk Space Used By Exchange, v2

Long ago and far away (way back in 2006) I wrote an article for finding the disk space used by Exchange 2000 and Exchange 2003, Finding disk space used by Exchange. While this worked through a few Exchange 2007 betas, by Exchange 2007 RTM, the STM file had been removed, and the original script would bomb, making the script only useful for Exchange 2000 and Exchange 2003.

Astute VBscript users would determine how to comment out the few lines causing the issue, but for most folks, that was too much.

So, I finally updated that script for Exchange 2007 and Exchange 2010 (tested on both) and updated it to PowerShell.

This is the script:

function build-object( [string]$server, [string]$edbfilepath, [string]$displayName )
{
	write-debug "build-object enter"
	write-debug "build-object server: $server"
	write-debug "build-object edbfilepath: $edbfilepath type $($edbfilepath.gettype().ToString())"
	write-debug "build-object displayName: $displayName"
	write-debug " "

	$o = "" | Select Name, Display, Length
	$o.display = $displayName

#	if( $server -eq $env:ComputerName )
	if( 0 )
	{
		$r = dir -ea 0 $EdbFilePath
	}
	else
	{
		$filename = "\\" + $server + "\" + $edbfilepath.SubString( 0, 1 ) + 
			"$" + $edbfilepath.SubString( 2 )
		write-debug "Calculated filename: $filename"
		$r = dir -ea 0 $filename
	}

	$o.Name = $r.Name
	$o.Length = $r.Length

	write-debug "build-object exit"
	return $o
}

Get-Command Get-ExchangeServer -ea 0 | out-null
if( ! $? )
{
	write-error "You must run this script within an Exchange Management Shell"
	return
}

$legacy = Get-ExchangeServer $env:Computername -ea 0
if( ! $? )
{
	write-error "You must run this script on an Exchange server"
	return
}

$org = $legacy.ExchangeLegacyDN.SubString( 3 )
$org = $org.SubString( 0, $org.IndexOf( '/' ))
"Exchange Organization Name: $org"

$default = ( Get-AcceptedDomain |? { $_.Default -eq $true } ).DomainName
"Default SMTP Domain: $default"

$forest = $legacy.DistinguishedName.SubString( $legacy.DistinguishedName.IndexOf( 'DC=' ) )
"Active Directory Forest: $forest"
" "
"All Exchange Servers in forest"
$servers = Get-ExchangeServer | select Name
foreach( $server in $servers )
{
	"`tName: $($server.Name)"
}
" "
"All Mailbox Servers in forest"
$mailbox = Get-ExchangeServer |? { $_.ServerRole -match "Mailbox" } | Select Name, IsMemberOfCluster
foreach( $server in $mailbox )
{
	"`tName: $($server.Name)"
}
" "

"Acquiring size of databases..."
" "
[int64]$totalSize = 0
foreach( $server in $mailbox )
{
	"Server name: $($server.Name)"

	[int64]$serverSize = 0
	$serverArray = @()

	if( $server.IsMemberOfCluster -eq 'Yes' )
	{
		$mailboxServer = Get-MailboxServer $server.Name -ea 0
		$myServer = $mailboxServer.RedundantMachines[0]

		$serverArray += (get-mailboxdatabase      -server $server.Name -ea 0) |% {
			build-object $myServer $_.EdbFilePath $_.AdminDisplayName;
		}

	}
	else
	{
		$serverArray += (get-mailboxdatabase      -server $server.Name -ea 0) |% {
			build-object $_.Server $_.EdbFilePath $_.AdminDisplayName;
		}
	}

	$serverArray += (get-publicfolderdatabase -server $server.Name -ea 0) |% {
		build-object $_.Server $_.EdbFilePath $_.AdminDisplayName;
	}

	$serverArray |% { $serverSize += $_.Length }

	foreach( $element in $serverArray )
	{
		if( $element )
		{
			"`tDatabase name: $($element.Display)"
			"`t`tEDB File: $($element.Name)"
			"`t`tEDB size: {0} bytes, {1} GB" -f $element.Length.ToString("N0"), ($element.Length / 1GB).ToString("N3")
			#$element
		}
	}
	"Total size of databases on server {0} bytes, {1} GB" -f  $serverSize.ToString("N0"), ($serverSize / 1GB).ToString("N3")
	" "
	$totalSize += $serverSize
}

"Total size of all databases in organization {0} bytes, {1} GB" -f  $totalSize.ToString("N0"), ($totalSize / 1GB).ToString("N3")

 

Until next time…

As always, if there are items you would like me to talk about, please drop me a line and let me know!


Follow me on twitter! : @EssentialExch

More on Active Directory Privileged Groups and Exchange Server

In October of 2008, I wrote the article adminCount, adminSDHolder, SDProp and you! This article discussed why membership in privileged groups could cause permissions challenges. You may want to refer to it before proceeding.

With Exchange Server 2010, the overall situation has continued to get more restrictive. Exchange Server 2010 needs for users who have mailboxes to inherit permissions in order for Role-Based Access Control (RBAC) and overall Exchange access to work properly. Membership in a privileged group will stop a mailbox from inheriting permissions. Usually, normal mailbox access will work fine (i.e., using Outlook with MAPI) due to historical permissions present on a mailbox, but any other IIS based or MAPI service will fail. This includes, but is not limited to, Blackberry Enterprise Server, Exchange ActiveSync, Outlook Web App, etc.

You can see a complex way of working around this issue described in KB Article 907434: The “Send As” right is removed from a user object after you configure the “Send As” right in the Active Directory Users and Computers snap-in in Exchange Server.But that method is an administrative nightmare.

Realistically speaking – what can you do?

The answer is simple: Get your users out of privileged groups.

No user who is Administrator, a Domain Admin, an Enterprise Admin, or a Schema Admin should be signing into Exchange with an account that is a member of those groups. This is also true for any member of the Built-in\Administrators group that exists on Domain Controllers. Every user who has access to a high-privilege account should also have a normal user account that they use for day-to-day usage – just like everyone else.

For the other privileged groups (Account Operators, Server Operators, Print Operators, Backup Operators, Cert Publishers) – these are legacy groups. They are a carry-over from Windows NT. Don’t use them. Instead, use a computer’s Local Security Policy – or a Domain Security Policy when appropriate – to assign users who need those capabilities the specific rights they require.

Usually, you will find that the built-in groups provide more power than you think they do (e.g., a member of Account Operators, Server Operators, Print Operators, or Backup Operators can log in locally to a domain controller and shut it down). Mapping between the groups is fairly simple by examing User Rights Assignments in any Local Security Policy. An online version of this is available at: http://technet.microsoft.com/en-us/library/bb726980.aspx in tables 7-7, 7-8, and 7-9.

You may not normally consider <insert-any-group-name-here> to be a privileged group. But Active Directory does. Get users out of privileged groups where possible, and where not possible – assign (and require use of!) users a normal account and a privileged account.

Until next time…

As always, if there are items you would like me to talk about, please drop me a line and let me know!


Follow me on twitter! : @EssentialExch

Moving a Mailbox Database Path

In Exchange 2007 and Exchange 2010, added functionality in Move-Mailbox (and New-MoveRequest), along with the support of online mailbox moves, have reduced the requirement of moving entire databases around very much (it’s easier to just move all the mailboxes in the mailbox database to a new mailbox database in the proper location).

But sometimes – you just need to do it. Even with the downtime it may cause.

You CAN do it from the Exchange Management Console or from the Exchange Management Shell. However, the provided status information is worthless. You have no idea how far along the data movement is. What I recommend instead is this process:

  1. Dismount the mailbox database
  2. Use ROBOCOPY to copy the database file from the old location to the new location
  3. Use Move-DatabasePath -ConfigurationOnly to update Exchange with the new location of the database
  4. Mount the mailbox database

In pseudo-PowerShell:

  1. dismount-database <dbname>
  2. robocopy <src-dir> <dest-dir> <dbname>.edb
  3. move-DatabasePath -Id <dbname> -ConfigurationOnly -EDBFilePath <new-full-path-to-edb>
  4. mount-database <dbname>

ROBOCOPY provides excellent information as to the status of a filecopy.

Also note that “ESEUTIL /y” is a good solution for copying large files as well. It provides respectable filecopy status information.

Until next time…

If there are things you would like to see written about, please let me know.

Edit November 22, 2010 – I’m extremely embarassed. In the original version of this post I used “unmount-database” (which doesn’t exist, of course) instead of “dismount-database”. Thankfully, only a few dozen people pointed out my error to me.


Follow me on twitter! : @EssentialExch