Archive for the ‘Networking’ Category

Windows 8 connect to VPN before logon

Last year I did an article entitled “Connect to a Windows VPN at logon”.  Rather than duplicate, please refer to that article for details, but It has been pointed out the method outlined is not available in Windows 8.  Actually it is but Win 8 by default alters the standard domain logon that was present since Win NT of pressing “Ctrl+Alt+Del”.  Restore that and you will again have the option to connect to a VPN prior to logon so you authenticate to the domain, and have group policy and logon scripts applied.

To re-enable “Ctrl+Alt+Del” either open the Local Security Policy under Control Panel, Administrative Tools, or open the local Group Policy editor by entering in the “Run” box gpedit.msc.  The location of the policy is in pretty much the same location in both, and setting in one will update the other.

  • In the Local Security Policy editor (control panel) it is located under; Security Settings | Local Policies | Security Options | Interactive logon: Do not require CTRL+ALT+DEL
  • In the local Group Policy editor (gpedit.msc) it is located under; Computer Configuration | Windows Settings | Security Settings | Local Policies | Security Options | Interactive logon: Do not require CTRL+ALT+DEL

The default state of the policy in Win 8 is “Not Defined” which on a domain joined computer effectively results in enabled.  You need to set the policy to disabled which will force the use of “Ctrl+Alt+Del”.   After doing so, I recommend running from an elevated command prompt  gpupdate /force, though it should not be necessary when editing the local policy.  On that note; you can enforce the use of “Ctrl+Alt+Del” domain wide by creating a GPO on your Domain Controller and editing the same policy.

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Once you do so, and log off, you will see the familiar “Press Ctrl+Alt+Delete to sign in” message in the top left corner of the logon screen.

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After pressing “Ctrl+Alt+Del” there will be a small network icon in the lower left corner

VPNCapture2

Click on the network icon and you will be presented with any VPN connection created on that computer.  Note these VPN connections must have been created using the “Allow other people to use this connection” option.  This discussion also applies only to domain joined computers.

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Enter you domain credentials, the VPN will connect, authentication to the domain will be processed, and group polices and logon scripts, including your mapped drives, will be pushed to the client.

 

UPDATE:  Should the PC not be domain joined and you wish to automate the VPN connection, please see: https://blog.lan-tech.ca/2013/06/08/rasdial-automate-vpn-connections/

Access local and VPN network Simultaneously

There are constantly questions in various forums; “how do I maintain internet access through my local router while connected to a VPN”, or “ how do I access my local TCP/IP printer while connected to a VPN”.  It is pretty basic but for those that don’t understand I thought I would address this in a blog so that in future I can just provide a pointer.

There is a security feature in almost all VPN configurations that blocks all local network connections while connected to the corporate network, via a VPN.  This is to provide some degree of security by preventing someone with malicious intent from reaching the corporate server using your PC/Laptop as a stepping stone.   It basically isolates your device from the world around you so that Johnny playing video games in the next room cannot route traffic through your PC to the corporate site.  Or, consider an Internet Cafe’ where you are on the same local network as total strangers.   Either through the shared Wi-Fi connection, or even an “Ad Hoc” wireless connection, the person at the next table could conceivably route packets through your wireless device directly to head office.  Granted, there are many security features in place, or at least there should be, such as firewalls and NTFS security permissions to protect your corporate data, similar to the security corridor from the 60’s & 70’s TV show Get Smart, but the more of these doors left open, the easier it is for hackers.  Everything can be hacked.  If you don’t believe me have a look at the following Ted Talks video by Avi Rubin; “All your devices can be hacked”.

In order to simultaneously access the local and remote VPN network you need to enable a feature called split-tunneling.  Due the security reasons outlined above, I do not recommend enabling this, however in some cases it is necessary or perhaps you just wanted to know why.  If you have an Enterprise VPN solution such as Cisco, Watchguard, Sonicwall, or others, as an end user cannot enable split-tunneling.  It is managed by the VPN appliance and will require the administrator to configure and enable if they see a need to do so.   However if you are using a Windows VPN client you can edit the configuration to allow split-tunneling.  To do so open Control Panel, select Network and Sharing Center, and then choose “Change Adapter Settings”.   This will work on XP and earlier clients as well but the path to the adapters is slightly different.  Locate the VPN/PPP adapter, right click on it and choose properties.  In the resulting window select Networking, highlight Internet Protocol Version 4 (TCP/IPv4) and click properties, click Advanced, and in the resulting window un-check “Use Default Gateway on remote network.  When checked, its default state, it forces all traffic through the remote site.  Un-checking allows access to the local network and gateway.

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Again remember this is a security feature and should not be reconfigured unless necessary and you are aware of the risks.

Configure Siemens SE567 router to allow VPN access

 

I have been asked a few of times how to configure a BellAliant Siemens SE567 router / modem to allow VPN access to a server, using PPTP.

When accessing a PPTP VPN server through a router, three primary conditions must exist.  Numbers 1 and 2 we can configure, 3 is dependent on your ISP.

  1. The router must be configured to  forward PPTP traffic to the VPN (RRAS) server using port 1723
  2. The router must be configured to allow GRE traffic (Generic Routing Encapsulation).   GRE  like, TCP and UDP, is a protocol.  GRE is protocol 47, not port 47 which is often incorrectly documented.  GRE is not really forwarded like services, but rather enabled.
  3. The ISP must allow PPTP/GRE traffic.  A few ISP’s intentionally block PPTP/GRE traffic.

GRE is enabled in different ways on different routers. Some have an option “Enable PPTP pass-through” others you forward the PPTP service which includes port 1723 and enabling GRE, and still others require specific commands.  The Siemens SE567 requires two rules, one for PPTP and one for GRE.  Generally Bell Aliant does not block this traffic.

Log into the Seimens unit and click “Advanced” at the top, then “Applications” on the left, followed by “Port Mapping Setup” in the menu.

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First select the application “PPTP” and in the “redirect selected protocol/application to IP Address” box put the IP address of the server, in this case 192.168.2.20, and click “Apply.”

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Next in the protocol box select GRE and again in the “redirect selected protocol/application to IP Address” box put the IP address of the server.

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Done !

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Note:  the other ports shown in the example, 443 and SMTP/25, are unrelated to the PPTP VPN and just there to show other service configurations.

Canadians – Win a Trip for Two to Mexico!

Microsoft Canada has created a great opportunity for free on-line training in Microsoft Private Cloud services, while at the same time entering your name for a chance to win a trip for two to Mexico.  Free evaluation software is available for System Centre 2012, Windows Server 2008 R2 SP1, and Windows Server 2012 RC, as well as 6 free Virtual Academy courses, and 14 guided labs to introduce you to the Microsoft Private Cloud.

Keep in mind contest regulations state; “Sweepstakes is open to individual legal residents of Canada “ so your odds of winning are far greater than with global sweepstakes.

Learn About The Microsoft Private Cloud to Win a Trip for Two to Mexico!

Mexico2Microsoft has released new and exciting products that will change the way IT Pros utilize Virtualization and Microsoft Private Cloud solutions.   Two products which are a part of these great changes are the newly released System Center 2012 and the soon to be released Windows Server 2012.  Both of these solutions were designed to make virtualization and extending to the private cloud simpler and much more efficient.

With these new changes to Infrastructure and the IT world, it’s a great time to learn about these new solutions and keep yourself and your organization ahead of the curve in terms of where technology is headed.  In fact, Microsoft has even added an incentive to learn about their Private Cloud solutions through the Skyrocket Sweepstakes!

Entering is easy!  All you have to do is register, and then download a free TechNet evaluation like Windows Server 2012 RC or System Center 2012 to get started.  Every applicable evaluation you download gives you an entry into the sweepstakes! And the best part is the more evaluations you download, the better your chances.  And what’s the prize you may ask? Oh, just a 7 day, 8 night trip for two to Cozumel, Mexico!

The contest ends September 6th so don’t wait!  Register now!

How to join a Windows Domain using a VPN

There may be occasions where you need to join an off-site computer to an existing domain at a remote office.  Most often this would be in a situation such as a satellite office which is part of a larger corporate network and there is a site-to-site VPN in place.  Though a site-to-site VPN is by far the easiest way to join, it can be done using a Windows VPN client, which will be discussed further on in this article.  The primary problem encountered when joining the domain is DNS, but this is easily dealt with.

Joining the domain using a site-to-site VPN

  • Only 1 network adapter can be enabled on the PC joining the domain, and preferably a wired connection.  If any others exist such as a wireless card, disable until domain joined.  On occasion Bluetooth adapters will also conflict, so I recommend disabling them as well.
  • Configure the connecting PC’s network adapter either statically or through DHCP to point ONLY to the domain controller at the corporate office for DNS.  Do not add an alternate external DNS server such as an ISP or router as these will often respond first and name resolution will fail.
  • In the NIC configuration, under Internet Protocol Version 4 (TCP/IPv4) properties, click advanced, and under the DNS tab insert the corporate internal DNS suffix, such as CompanyDomain.local in the box entitled “DNS suffix for this connection”
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  • Then join the domain using the traditional method of Computer (formerly My Computer) | Properties | Change Settings |  Change | enter the internal domain name | click OK | and you should be prompted for credentials for an account authorized to do so, a Domain Admin account.  If the Domain Controller is a version of Small Business Server the SBS option to use  http://SBSname/connectcomputer  or http://connect most often will not work.  (more detail and screen shots for the joining the domain process can be found below in the using a VPN client section).
  • If you wish to simultaneously import an existing local user profile, you can use ProfWiz as outlined in the following link which will both join the domain and move the profile. Though the article references SBS, it can be used with any Windows Server Version.  https://blog.lan-tech.ca/2011/05/19/sbs-and-profwiz/

Joining the domain using a Windows VPN client

Joining a domain using a VPN client is a little more involved, but not complicated. This method may work with other VPN clients, so long as they have the option to connect to the VPN before logon, but this explanation uses only the Windows built-in VPN client.  Without the ability to connect before logon, there is very little advantage even if you can join the domain, as you would not actually be authenticating to the domain.  I will assume the server end, RRAS, is configured and working for VPN client connections.

  • Log on to the PC you wish to join the domain with a local administrator account
  • Only 1 network adapter can be enabled on the PC joining the domain, and preferably a wired connection.  If any others exist such as a wireless card, disable until domain joined.  On occasion Bluetooth adapters will also conflict, so I recommend disabling them as well.
  • Establish a VPN connection.  If not familiar with doing so:
    • From the network and sharing center choose “Set up a new connection or Network”
    • Select “Connect to a workplace”
    • Choose “Use my Internet connection (VPN)”
    • Enter the public facing FQDN of the corporate VPN server such as VPNserver.MyDomain.com and enter a friendly name for the connection, anything you like.  It is also very important to check the box “Allow other people to use this connection” as you will soon have a domain account which will require access to this VPN connection.
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    • Enter a User name, which ideally is the user that will be using the connection once joined to the domain, but can be any user name that is authorized to connect to the corporate network via VPN.  If you use a name other than the ultimate user of the PC they will simply have to change the user name during in the connection wizard, the first time they try to connect.  Enter the password and choose connect.  For security reasons I don’t recommend checking “Remember this password”.
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    • If prompted for a network type after connecting, choose “Work Network”.

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  • Presumably you were able to establish a connection.  However while connected if you did an NSlookup from a command line for the server name, you will see it fails. Try an NSlookup for the FQDN of the server, and it will succeed.  Thus, we need to configure DNS for the VPN clientbefore proceeding.
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    • Disconnect the VPN client
    • In the network connections window right click on the VPN/PPP connection and choose properties | Networking tab | highlight Internet Protocol Version 4 (TCP/IPv4) and choose properties | Advanced | DNS tab | and enter the IP of the corporate DNS server under DNS server addresses and the internal domain suffix such as MyDomain.local in the “DNS suffix for this connection box.  If admins need to connect to the remote client PC for administration by name check the box “register this connection’s address in DNS” but I would discourage this as the IP can change frequently and cause issues.  Also on the “IP Settings” tab leave the option “Use default gateway on remote network” checked, at least for now, so that all traffic is forced to the corporate network while the VPN is connected.
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  • Now you can try joining the domain
    • Connect the VPN client
    • Right click on “Computer” (formerly My Computer) and choose properties.
    • In the resulting window select “Change Settings”
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    • Slect “Change” again
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    • Enter the corporate internal Domain name, such as MyDomain.local in the Domain box and click OK
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    • You will be prompted for a domain account with privileges to join a PC to the domain, a Domain Admin.  Enter it and the password and you should receive a message advising you have been joined to the domain.  Be patient it takes a little longer as this is a slow link compared to the LAN.
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    • You now need to reboot the connecting PC.
  • In order to authenticate to the corporate network at logon and work as if on the corporate LAN, you need to connect the VPN before logging on to the PC.  When the PC reboots press Ctrl+Alt+Delete as you normally would, and then choose  “Switch User”
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    • You will then be presented with a new option, a little blue icon in the lower right corner.
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    • Clicking this allows you to choose to connect to the corporate network, by using the VPN.  After entering your credentials you will see the familiar VPN connection automatically start, it will connect, and you will be authenticated to the domain.
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    • Logon is a little slower of course due to the slow link, and the first time you connect it will have to set up the local domain profile.  If you make use of redirected my documents, offline files, or have a lot of group policies logon can take a very long time while they apply and sync.  If logon is too slow, you may want to review options available to the remote user.  You will note that if you now try nslookup <servername> works as it should.

Note:  If connecting from Windows 8, please see the following updated article:  https://blog.lan-tech.ca/2013/03/02/windows-8-connect-to-vpn-before-logon/

 

Depending on the performance of the VPN connection, it is sometimes necessary for the network administrator to “tweak” a few Group Policies for slow network detection. The following policies can assist with this:

Server 2008 / 2008 R2 / SBS 2008 / SBS 2011:
  • Computer Configuration | Policies | Administrative Templates | System | Group Policy | Group Policy slow link detection
  • Computer Configuration | Policies | Administrative Templates | System | Scripts | Run logon scripts synchronously
  • Computer Configuration | Policies | Administrative Templates | Network | Offline Files | Configure slow-link mode
  • Computer Configuration | Policies | Administrative Templates | Network | Offline Files | Configure slow link speed
Server 2003 / SBS 2003 / SBS 2003 R2:
  • Computer Configuration | Administrative Templates | System | Logon | Always wait for the network at computer startup and login
  • Computer Configuration | Administrative Templates | System | Group Policy | Group Policy slow link detection
  • Computer Configuration | Administrative Templates | System | Scripts | Run logon scripts synchronously
  • Computer Configuration | Administrative Templates | Network | Offline Files | Configure slow-link mode
  • Computer Configuration | Administrative Templates | Network | Offline Files | Configure slow link speed

 

Toast For Our Tables

Remotely change DNS server IP’s

I was recently asked how to change the DNS server IP’s in the NIC configurations of numerous servers, which of course have static IP’s.  Sounds simple right?  Maybe not.

  • You can use Group Policy to do so but apparently it will not work with all O/S’s and it will only work if DNS is working. 
  • You can deploy a script but that requires logon or reboot to apply. 
  • You use psexec and a text file list of servers with something similar to: “psexec @textfilename netsh interface ip set dns name = “Local Area Connection” source = static addr = 1.1.1.1”  however it requires the NIC name be accurate and it is not always named “Local Area Connection”

One proposed great solution is to use a VBS script by Alexxxandre K8L0 on TechNet.  This uses a text file list of server names or IP’s and updates each in the list.  The article can be found in the following link, but since occasionally the links change or articles ‘disappear’ I have posted the content here, but I take no credit for its design: http://gallery.technet.microsoft.com/scriptcenter/Change-fixed-DNS-IP-of-422415c1

Syntax: cscript SetDNSv2.vbs inputfile outputfile dns_ips
Input file: Put IP or Hostname of server line by line on a text file.
Output file: Is a log of return status “Inputed,Host,Adapter,Return Status”
dns_ips: Ips of DNS Servers separated by commas.
Example: cscript SetDNSv2.vbs inputfile.txt outputfile.txt 10.1.0.10,10.1.0.11,10.1.0.10

‘Set DNS By k8l0
‘By k8l0
If WScript.Arguments.Count = 3 Then
    strInputFile = WScript.Arguments.Item(0)
    strOutputFile = WScript.Arguments.Item(1)
    strNewDNS = WScript.Arguments.Item(2)
Else
    wscript.echo “Sintaxe: cscript SetDNSv2.vbs inputfile.txt outputfile.txt 10.1.98.64,10.1.98.36,10.1.18.24”
    wscript.quit
end if    
 
On error resume next
 
Const ForReading = 1
Const ForAppending = 8
 
Set objFSO = CreateObject(“Scripting.FileSystemObject”) 
Set objTextFileIn = objFSO.OpenTextFile(strInputFile, ForReading)
Set objTextFileOut = objFSO.OpenTextFile(strOutputFile, ForAppending, True)
 
wscript.echo “Host        Adapter        Return Status”
wscript.echo “—-        ——-        ————-”
objTextFileOut.WriteLine(“Inputed,Host,Adapter,Return Status”)
 
Do Until objTextFileIn.AtEndOfStream 
    strComputer = Trim(objTextFileIn.Readline)
    
    Set objWMIService = GetObject(“winmgmts:” & “{impersonationLevel=impersonate}!\\” & strComputer & “\root\cimv2”)
    Set colNicConfigs = objWMIService.ExecQuery(“SELECT * FROM Win32_NetworkAdapterConfiguration WHERE IPEnabled = True”)
    
    For Each objNicConfig In colNicConfigs
        If Not IsNull(objNicConfig.DNSServerSearchOrder) Then
            strReturn = “”
            arrNewDNSServerSearchOrder = Split(strNewDNS,”,”)
            intSetDNSServers = objNicConfig.SetDNSServerSearchOrder(arrNewDNSServerSearchOrder)
            If intSetDNSServers = 0 Then
                strReturn = “””” & “Replaced DNS server search order list to ” & strNewDNS & “.” & “”””
            Else
                strReturn = “Unable to replace DNS server search order list.”
            End If
        Else
            strReturn = “DNS server search order is null. Nothing changed!”
        End If
        
        strDNSHostName = objNicConfig.DNSHostName
        strIndex = objNicConfig.Index
        strDescription = objNicConfig.Description
        strAdapter = “Network Adapter ” & strIndex & ” – ” & strDescription
        wscript.echo strDNSHostName & VBTab & strAdapter & VBTab & strReturn
        objTextFileOut.WriteLine(strComputer & “,” & strDNSHostName & “,” & strAdapter & “,” & strReturn)
        Next
Loop 
 
objTextFileIn.close
objTextFileOut.close
 
wscript.echo “Finished!!!”

Remote PC firewall on or off ?

I was asked; “how can I tell from a command line if the firewall is enabled on a PC on our network, using a command line?”

Netsh is a very powerful tool for querying and setting the status of most anything network related. There are both the ‘netsh firewall’ and ‘netsh advfirewall’ options depending if XP, or Vista and newer.  I will deal with the advanced firewall as it is commonly used with Vista and Win 7 these days. The following command will return the available options:

C:\>netsh advfirewall show

The following commands are available:

Commands in this context:
show allprofiles – Displays properties for all profiles.
show currentprofile – Displays properties for the active profile.
show domainprofile – Displays properties for the domain properties.
show global    – Displays the global properties.
show privateprofile – Displays properties for the private profile.
show publicprofile – Displays properties for the public profile.
show store     – Displays the policy store for the current interactive session.

As you are aware the Advanced firewall can be set differently for domain, home, or public networks.  We are concerned with how it is set now, while on our network so we will use the show currentprofile option.  The result returns numerous details. By piping the results to the find command we can limit the output and simply determine if the Windows firewall is on or off  ( note: /I ignores case of the text in quotes):

C:\>netsh advfirewall show currentprofile |find “State” /I
State                                 OFF

Chances are you will not want to run to the machine to check so you can make use of Sysinternals/Microsoft’s PSexec to run netsh, or any command, on a remote machine.  You will need to run this with admin privileges for the remote machine. Therefore it is generally done from the server using a domain admin account.

C:\PSTools>psexec \\PC1 netsh advfirewall show currentprofile |find “state” /I

PsExec v1.98 – Execute processes remotely
Copyright (C) 2001-2010 Mark Russinovich
Sysinternals – http://www.sysinternals.com

Starting netsh on PC1…ice on PC1…
State                                 OFF
(the output will often end with the following when run remotely: netsh exited on PC1 with error code 0.)

PSexec can be downloaded for free from: http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx

SBS connect / connectcomputer wizard fails

Generally when a computer cannot join the domain using http://connect (SBS 2008 & 2011) or http://SBSname/connectcomputer (SBS 2003) it is due to inability to correctly resolve the name of the domain controller in a timely fashion. Below is a list of common reasons for the connect wizards to fail.

In an SBS domain, the server should be the DHCP server, and if so, items 3 and 4 below should be automatically set through DHCP.  However if addressing is statically assigned or you are using a router you may need to make changes. Items 3 and 4 are also basic networking requirements of a Windows Domain, not just important for joining the domain.

1. If there is more than 1 network adapter installed, wired or wireless, disable all but 1 until domain joined.  If at all possible, make it a wired connection, not wireless. 

2. Many new PC’s also show a Bluetooth connection under “Network Connections”, this should be disabled as well while running the wizard.  If you are using a Bluetooth mouse and/or keyboard these will have to be temporarily replaced.

3. Make sure, using IPconfig /all, that the client’s DNS points ONLY to your internal DNS servers, in this case the SBS.  Do not allow a router or ISP to be added even as an alternate.

4. IPconfig /all should also show next to “Primary DNS Suffix”” your internal domain suffix such as MyDomain.local.  If not you need to add the domain suffix to the client machine. To do so insert it in the “DNS suffix for this connection” box under the DNS tab of the NIC’s advanced TCP/IP IPv4 properties

5. If there are any 3rd party firewalls or security suites installed, disable them until joined to the domain.  The Windows firewall should not need to be disabled.

6. If still failing add the connect web site to the “trusted” sites list in Internet Explorer under Tools | Internet Options | Security |trusted Sites

7. If all else fails you can skip the wizard and use a 3rd party utility called ProfWiz.  

It is important to note that using the connect and connectcomputer wizards is very important.  With SBS 2003 it is especially critical to do so as it performs a long list of tasks other than just joining the domain.  It copies the local user’s profile, configures the user and computer environments, changes permissions, installs SBS related features, makes changes to networking, and much more.  Susan Bradley’s blog outlines this in detail: “So exactly “what” does connect computer do anyway?”  However SBS 2008 and SBS 2011 control most of this through Group Policy.  The key bonus feature with the SBS 2008/2011 wizard is its ability to import current users’ local profiles. Though I still strongly recommend using the wizard, it will only import a local workgroup profile.  If the wizard fails or you are wanting to import a previous domain profile, you may want to consider using Profwiz.  Profwiz by forensit.com a simple little tool that will join the PC to the domain and reset the permissions of an existing profile allowing it to be used as the new domain profile (i.e. import users settings like desktop items, favorites, Documents, and application configurations). For instructions on downloading and running see:  https://blog.lan-tech.ca/2011/05/19/sbs-and-profwiz/

SBS 2008 / 2011 adding an SSL certificate

[Note: some links point to SBS 2008 configurations, some to SBS 2011, the procedure is the same for both]

Just a quick comment to address the many internet posts suggesting that SBS requires a multi-name SSL certificate (UCC – Unified Communications Certificate).  This is not true.  SBS is designed to use a simple, inexpensive, single name certificate, and it is quite easy to install.  A basic GoDaddy or other vendor certificate is all that is required.  Sean Daniel outlines the process very nicely in his post entitled “Installing a GoDaddy Standard SSL Certificate on SBS 2008 “.  Keep in mind the FQDN for your site as recorded in your public DNS records, the certificate name, and public name used in the “Internet Address Wizard” (see step #7), all must be exactly the same.  As a mater of fact, although it is possible to use a UCC certificate, the wizard will not install it for you, you would have to do so manually.  There is no need for the additional cost or time involved with multi-name certificates.  (The link below will take you to the Godaddy site and should have a menu bar at the top offering you a very good first year discount)

Go Daddy $12.99 SSL Sale!

The primary argument for using a UCC cert is to make use of auto-discovery.   Though you do not need auto-discovery, if you wish to make use of it you still do not need a UCC certificate.  You can in fact configure auto-discovery using a single name certificate and creating an SRV DNS record by following the ThirdTier.net instructions; “Setting up Autodiscover for SBS 2011

Alternatively, you can avoid buying an SSL certificate at all.  After running the SBS “Internet Address Management Wizard”, a self-signed certificate is generated in the SBS Share: \\SBSname\Public\Downloads\Certificate Distribution Package  .  Machines that are joined to the domain after this will have the certificate automatically installed.  If you generate a new certificate (by re-running the wizard), or have non-domain joined computers or devices, you need to manually copy and install the certificate.  To distribute / install the certificate on the PC’s, please see “How Do I Distribute the SBS 2008 Self-Signed SSL Certificate to My Users?”  This is often not as easy to do on other devices such as smart phones.  Therefore using a 3rd party certificate becomes much more attractive, as nothing has to be installed on the connecting device.

Should you have a dynamic public IP at the SBS site, I recommend reading “Using DDNS services with SBS 2008/2011” which outlines using a dynamic IP, a DDNS service, and configuring DNS and certificates.

Ping command…..needs to close

I had a client today advise they were unable to send or receive e-mail using Outlook.  Upon initial inspection this was the case and Outlook showed as disconnected (using Exchange).  There were no other obvious issues, web browsing and all network services “seemed” to be working properly.  However, there were frequent pop-ups with the message:   

TCP/IP ping command has encountered a problem and needs to close

Pinging did work fine, for the record. While doing a quick search for possible solutions I came across many others with a similar problem, so I thought I would take a moment to post my findings. 

The Event logs had additional errors the key one being:  Event ID: 4226,  Source: Tcpip,  TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts.

Though there could be other causes, this usually indicates some sort of malware, as confirmed by EventID.net 

Kaspersky’s Anti-rootkit utility TDSSKiller located 2 viruses, and AVG a third as shown in the image below. Keep in mind other viruses could present themselves in the same way.  Clearing all temp folders and a full scan by multiple other malware detection apps did not reveal any other issues, but one must always be concerned that “once infected, always suspected”.   Outlook now worked properly with no repairs required to the application or networking.

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