Archive for June, 2011

Small business environments and backup – HP RDX backup solution

Sunday, June 26th, 2011

In SBS enviroments there is always problem with backup solutions that are afordable and reliable at the same time. HP has an excelent, quick and robust solution that you can easily implement in SBS environment. It’s called HP RDX and you can check HP website for more info – it is composed of internal or external device and hard disk based cartridge of different sizes. It allows you to copy at a speed between 20-35 MB/s or better around 100 GB / hour…

If you have virtualised SBS environment so you are running SBS 2008 or SBS 2011 on Hyper-V platform you can backup your SBS server by using iSCSI on Hyper-V host (you can try with their fantastic iSCSI solution). When you have this software installed you can connect your RDX drive to your guest SBS server and use it to perform standard SBS backup on it.
This kind of solution will not work with Microsoft iSCSI target 3.3 (this is MS free iSCSI target that runs on Windows server 2008 R2) as it does not allow to use removable disks as source for iSCSI target disks (it only supports non-removable drives).

Windows server 2008 / 2008 R2 AD sync with external NTP server

Friday, June 24th, 2011

As AD servers provide time to machines in a domain it is important to have AD servers synchronized with an realyable time source. If you know the project you can find NTP servers that are part of this “cluster” and are near to you. As I live in Slovenia we have a pool called in which you can find Slovenian NTP servers that are accurate enough to provide exact time (for those more familiar with NTP protocol in pool there you can find also most accurate stratum1 and stratum2 time servers…).

On AD server that is running Windows server 2008 / 2008 R2 you should run command prompt with administrative rights (right click / run as administrator).

First check difference between your server and external time source (in my example

Command: w32tm /stripchart / /samples:5 /dataonly

C:\>w32tm /stripchart / /samples:5 /dataonly
Tracking [].
Collecting 5 samples.
The current time is 24.6.2011 13:29:08.
13:29:08, +08.8351541s
13:29:10, +08.7976694s
13:29:12, +08.8065559s
13:29:14, +08.7534768s
13:29:16, +08.7956427s

Confiure your server to use external NTP time source for sync:

Command: w32tm /config /,0x8, /syncfromflags:manual /update

C:\>w32tm /config /,0x8, /syncfromflags:manual /update
The command completed successfully.

Force sync immediately:
Command: w32tm /resync

C:\>w32tm /resync
Sending resync command to local computer
The command completed successfully.

I will now retry the first command to see the results:

C:\>w32tm /stripchart / /samples:5 /dataonly
Tracking [].
Collecting 5 samples.
The current time is 24.6.2011 13:19:20.
13:19:20, +00.0485657s
13:19:22, +00.0415741s
13:19:24, +00.0380984s
13:19:26, +00.0342493s
13:19:28, +00.0310221s

My contribution to IPv6 day – Configuring IPv6 in Windows server 2008 R2 – video tutorial

Wednesday, June 8th, 2011

My contribution to IPv6 day will be this small “lab” test where I will show you some basic IPv6 configuration that you can do with Windows server 2008 R2.
Here are the videos:

IPv6 day – configuring IPv6 in Windows server 2008 R2 part 1 –
IPv6 day – configuring IPv6 in Windows server 2008 R2 part 2 –

What do we have in our LAB?

1. Windows server 2008 R2 with two network cards:
External – with IPv6, gateway and DNS configured
Internal – with IPv6 address only

External IP has internal class static routed on our Cisco router in front of Windows server external card.

2. Windows 7 machine with single network card that is connected to the same switch as servers’ internal card.

What will we do:

In the fist video:

First we will start with some basic checking of network configuration on server.
Then we will run netsh (I run a command prompt with “Run as administrator”) and go to
netsh / interface / ipv6

with command

show route we can see ipv6 routes currently configured – we would like to enable publishing of route that I have highlighted in the video.

set route PREFIX INTERFACE_NUMBER publish=yes

then we will run an command to enable advertising, to disable address management (so Windows 7 will generate IPv6 without help od DHCPv6) (M flag) and we will disable other stateful configuration (O flag).

set interface INTERFACE_NUMBER adv=enabled managed=disabled other=disabled

Meanwhile we are checking IPv6 connectivity from our Windows 7 machine… Windows 7 is still unable to ping outside the network…

well we need to configure some other stuff on server now… we will enable forwarding on our two interfaces (External and Internal)

set interface INTERFACE_NUMBER forwarding=enabled

still no connectivity from win 7? 🙂

last step that we need to do on our server is to advertise default route to our clients

set interface INTERFACE_NUMBER advertisedefaultroute=enabled

So our Windows 7 sudenly start to recive ICMPv6 echo replyes from some IPv6 machine outside our network WUHU! 🙂

But Windows 7 machine is not able to resolve hostnames to IPV6 addresses – this is becouse we have now global IPv6 address configured and default gateway – so we have connectivity but we are not able to resolve hostnames as we do not have any DNS servers to do that.

On Windows server 2008 R2 I will start the installation of two roles – first DHCP role which I wil configure later and DNS role.

When the roles are installed I will configure so called forwarders on my DNS server so my clients will be able to use my server as a DNS server for their queries.

In the second video:

I will first flush IPv6 configuration on Windows 7 machine by using command
ipconfig /release6
ipconfig /renew6
(is the opposite command to regain IPv6 configuration)

Secondly I will configure DHCPv6 server by starting New Scope wizard under IPv6 settings…

I will configure prefix – this ipv6 prefix of Internal network card

Skip the exceptions and activate the scope…

You will see that Windows 7 still did not ask DHCPv6 servers for address this is becouse managed flag is set to disabled on server so…

in netsh / interface / ipv6 we need to activate managed flag by inserting this command:

set interface INTERFACE_NUMBER managed=enabled

Our Windows 7 machine can now be found in IPv6 leases on our DHCP server – but still it is unable to ping hostnames on the internet… This is becouse our DHCPv6 server is not giving DNS servers as scope options and Other stateful flag is disabled.

So we first need to add DNS Recursive Names Server IPv6 Address in our Scope options and then use netsh command:

set interface INTERFACE_NUMBER other=enabled

Yeeepppeee!!! Our Windows 7 is ready to ping hostnames on the internet – so it is able to surf the IPV6 internet…

When I am finishing this article is 8.6.2011 23:37 – this is my small contribution to IPv6 day so happy IPv6 day to all of you! 🙂