Windows Server 2012 introduces fundamental improvements that make it a cloud-ready operating system. The capabilities provide a flexible and scalable solution which opens up a wide range of opportunities for hosting providers to build new cloud services.
This blog post is co-authored by Uma Mahesh, Senior Program Manager and Yigal Edery, Principal Program Manager in the Windows Server division. The blog article is based on Yigal’s TechEd talk on “Building Hosted Public and Private Clouds Using Windows Server 2012”
In this post, Contoso.com, a Washington DC based fictitious company, replicates its business critical VMs to a hosting provider offering DR as a cloud service. This article describes integration between different Windows Server 2012 features to enable a complete end to end service which hosting providers (or ‘hoster’) can offer. It uses Hyper-V Replica, Network Virtualization and Remote Access (including both site-to-site (S2S) VPN & DirectAccess), which enables a hoster to build a complete, multi-tenant disaster recover (DR) service, using Windows Server 2012.
The technology building blocks are:
Hyper-V Replica: Hyper-V Replica in Windows Server 2012 allows you to replicate multiple VMs from different tenants on single physical host.
Hyper-V Network Virtualization: Hyper-V Network Virtualization allows a multiple tenant virtual networks with overlapping IP address space to be created on the same hoster physical network yet providing isolation between tenant network. A replicated VM of a tenant can be brought live in a dedicated virtual network for the tenant in the hosting provider’s physical network.
Site-to-Site VPN support: Using the S2S VPN solution which is available in Windows Server 2012 (which includes support for S2S VPN over IPsec), tenants can connect to their respective virtual network in the hoster premises.
DirectAccess with multi-pathing: Multi-Pathing enables employees of each tenants to connect to the on-premises DA under normal operations. If the replicated VMs are brought up in the hosting provider premises (say, due to a disaster in the tenant’s site), employees smoothly failover to the hoster DA server and through it to the replicated VMs in their respective virtual network with the hoster.
In this article, we will demonstrate the steps required to set up a deployment to replicate a mission critical app (which is hosted in a VM) from the customers premise to a hoster. When a disaster strikes the customer premises, the administrator fails over to the replicated VM (on the hosting provider premises) which comes up with the same IP address. Clients using DA can seamlessly be routed to the service that’s currently up and running in the hosting provider premises.
The topology is as follows:
Contoso.com’s Washington site consists of an:
Edge Gateway (EDGE1) is a Windows Server 2012 VM in which Remote Access is configured. EDGE1 connects to Internet via a NIC (188.8.131.52) which connects to the Internet Router (184.108.40.206). It also connects to rest of Contoso’s corporate network (10.0.0.0/24) via another NIC (10.0.0.2, 2001:db8:dc::1)
Domain controller DC1 (10.0.0.1, 2001:db8:dc::1)
Applications server APP1 ((10.0.0.1, 2001:db8:dc::1) run as VMs on another WS2012 Hyper-v Server (ContosoP1 – also referred to as the “Primary Server”). Hyper-V Replica is enabled on this (APP1) VM and the VM is replicated to a Windows Server 2012 Hyper-V server on the hosting provide premises (HosterR1 – also referred to as the “Replica Server”) .
Client1 is a client VM of Contoso that is connected to Internet (220.127.116.11)
DA is configured on Client1 which ensures that it can connect to Contoso’s corporate network and access applications like APP1. Client1 is not concerned whether APP1 is physically present in Washington site or in hoster network as it accesses the application by it’s name app1.corp.contoso.com using DireactAccess. Furthermore, it can connect to DA server in the enterprise viz, EDGE1 or connect to DA server of Contoso at the hoster premises 3-DAS1. If connectivity to any DA server is lost, the DA connection automatically reconnects to other active DA server.
HosterGW, which is running on Windows Server 2012, is connected to “Internet” (18.104.22.168). The hoster’s internal network is 192.168.1.101.
NAT is enabled on HosterGW so that applications/services (like Hyper-V Replica ) on hoster internal network (eg:HosterR1 ,192.168.1.101) are available over Internet. HosterR1 can host VMs directly created on it or replicated to it using Hyper-v Replica.
HosterGW machine hosts GW VMs per tenant so that the hoster can provide connectivity between the tenant’s virtual network and tenant’s on-prem network. In this topology, ContosoCloudGW VM is the S2S VPN GW for Contoso. This VM connects the contoso virtual network at hoster to the contoso corporate network. Hyper-V Network Virtualization is used to create the Contoso’s virtual network of 10.0.0.0/24, 10.6.0.0/24, 2001:db8:dc::/48 and 2001:db8:dc::/48 (collectively called the Customer Address space or CA) over the hoster’s address space 192.168.1.0/24 (called Provider Address space or PA).
Building the above deployment
Step 1: Building Contoso’s environment
This step is similar to creating the base environment for DA. The test lab guide which demonstrates Direct Access single server setup has detailed steps on creating the environment. Once the steps are completed, you will have a setup where Client1 from Internet (directly connected or behind NAT) can access APP1 over Direct Access as shown in the below diagram.
Step 2: Building Hosters’s environment
The objectives of the hosting provider are:
- Allow Contoso.com to bring VMs with an IP of their choice
- Connect Contoso VMs back to their on-prem network.
- Allow customers to replicate their on-prem VMs to the hosting provider
2a) Steps required to “bring your own IP address”
Hyper-V Network Virtualization (HNV) allows Contoso to bring VMs with an IP address to the hoster. The following cmdlets demonstrate how HNV can be deployed on two hosts viz., HosterGW & HosterR1.
In this example, HosterGW has two NICs one connected to “Internet” (22.214.171.124) and once connected to hoster internal network (192.168.1.101). HosterR1 has one NIC connected to hoster internal network(192.168.1.111). The following PS cmdlets need to be run on both HosterGW and HosterR1 to configure HNV.
On the HosterGW, run the following cmdlets:
On HosterR1, run the following cmdlets:
Step 2b: Connect Contoso VMs back to their on-prem network.
While the above steps create the necessary network infrastructure to create Contoso virtual network the following steps are required to create the VMs and ensure that the VMs are able to connect to Contoso on-prem network.
Create a Windows Server 2012 VM ContosoCloudGW with 2 VM NICs
Connect one VM NIC to the V-Switch connecting to Internet NIC (126.96.36.199) and another VM NIC to V-switch connecting to Internal NIC.
Configure MAC address of internal VM NIC as 00155d05df03
Configure the following IP address scheme:
- Assign IPv4 address 10.6.0.2/24 &2001:db8:6::2/64 to NIC connected to internal NI
- Create site-to-site VPN connections between ContosoCloudGw & EDGE1 using the following cmdlets
The above steps ensure that VMs of Contoso hosted @ the hoster are accessible from Contoso Washington site and Internet Via DirectAccesss from EDGE1.
Step 2c: Configure Hyper-V Replica
This replica server is ‘published’ using the hoster’s GW via regular HTTPS (customers use cert-based authentication to replicate).
The following links illustrate on how to achieve this:
Create certificates using makecert – Appendix C of the Understanding and Troubleshooting guide for Hyper-V Replica
(or) Create certificates from a standalone CA
(or) Create certificates from an Enterprise CA
Setup replication for the virtual machine using the certificate based authentication.
Since EDGE1 is acting as DA server it will not allow any non-IPsec traffic thru it. In general customer deployment there would be an IPS device in front of EDGE1. In the above topology to allow HTTPS HVR traffic thru EDGE1, we need to disable IPsec dosp with the following cmdlet
As Hyper-V Replica takes on the end-server name (not IP address) as input, you could resolve the server name by making an entry in the host file of ContosP1. To achieve this, add an entry in %systemdrive%\drivers\etc\hosts
Similarly on HosterR1, add the following entry in hosts file
Step 3: Configuring Cloud DA site on top of Hyper-v Network Virtualization:
Now that we have ensured the the VMs are replicated to the hoster we need to provide and option to Contoso employees to connect to their replicated VMs from Internet even if Washington DA server is not available. This is done by deploying a DA server in Contoso cloud. Since DA in WS 2012 supports multiple DA sites, all that’s required here is to enable a new Cloud DA entry point. Following diagram describes the topology.
Here are the steps to configure DA cloud site:
Configure NAT on 3-EDG1
- Open rrasmgmt.msc
- Right click on IPv4 general node
3. Click new Routing Protocol…
4. Select NAT
5. Right click on NAT node.
6. Select New Interface.
7. Select the interface connected to Internet.
8. In NAT tab, select Public Interface connected to private network and check “Enable NAT on this interface” option.
9. Select services and ports tab, select “Secure web server (HTTPS) option
Enter the IP address of 3-DAS1, 10.6.0.6 in Private address.
Configure IP address 10.6.0.6/24 (default route 10.6.0.2) & 2001:db8:2::/64 (default route 2001:db8:6::/64) with DNS server as 10.0.0.1/24, 10.2.0.1/24 & 2001:db8:1::1/64, 2001:db8:2::1/64 respectively.
1. In the Server Manager console, click Local Server, and then in the Properties area, next to Avez-CA-NIC , click the link.
2. Right-click Avez-CA-NIC, and then click Properties.
3. Click Internet Protocol Version 4 (TCP/IPv4), and then click Properties.
4. Click Use the following IP address. In IP address, type 10.6.0.6, in Subnet mask, type 255.255.255.0.
5. Click Use the following DNS server addresses. In Preferred DNS server, type 10.0.0.1, and in Alternate DNS server, type 10.2.0.1.
6. Click Advanced, and then click the DNS tab.
7. In DNS suffix for this connection, type corp.contoso.com, and then click OK twice.
8. Click Internet Protocol Version 6 (TCP/IPv6), and then click Properties.
9. Click Use the following IPv6 address. In IPv6 address, type 2001:db8:6::6, in Subnet prefix length, type 64. Click Use the following DNS server addresses, and in Preferred DNS server, type 2001:db8:1::1, in Alternate DNS server, type 2001:db8:2::1
10. Click Advanced, and then click the DNS tab.
12. In DNS suffix for this connection, type corp.contoso.com, and then click OK twice.
13. On the 2-Corpnet Properties dialog box, click Close.
Join 3-DAS1 to corp.contoso.com.. Configure 3-DAS1 as 3rd entry point (similar to step 12).
Obtain certificates on 3-DAS1
1. Click Start, type mmc, and then press ENTER.
2. In the MMC console, on the File menu, click Add/Remove Snap-in.
3. On the Add or Remove Snap-ins dialog box, click Certificates, click Add, click Computer account, click Next, click Local computer, click Finish, and then click OK.
4. In the console tree of the Certificates snap-in, open Certificates (Local Computer)\Personal.
5. Right-click Personal, point to All Tasks, and then click Request New Certificate.
6. Click Next twice.
7. On the Request Certificates page, select the Client-Server Authentication and the Web Server 2008 check boxes, and then click More information is required to enroll for this certificate.
8. On the Certificate Properties dialog box, on the Subject tab, in the Subject name area, in Type, select Common name.
9. In Value, type 3-DAS1.contoso.com, and then click Add.
10. In the Alternative name area, in Type, select DNS.
11. In Value, enter 3-DAS1.contoso.com, and then click Add.
12. On the General tab, in Friendly name, type IP-HTTPS Certificate.
13. Click OK, click Enroll, and then click Finish.
14. In the details pane of the Certificates snap-in, verify that new certificates with the names 3-DAS1.contoso.com and nls.corp.contoso.com were enrolled with Intended Purposes of Server Authentication, and a new certificate with the name 3-DAS1.corp2.corp.contoso.com was enrolled with Intended Purposes of Client Authentication and Server Authentication.
15. Close the console window. If you are prompted to save settings, click No.
Install the Remote Access role on 3-DAS1
1. Click Start, click Server Manager, and in the Dashboard, click add roles.
2. Click Next three times to get to the server role selection screen.
3. On the Select Server Roles dialog, select Remote Access, click Add Required Features, and then click Next.
4. On the Select features dialog, expand Remote Server Administration Tools, expand Role Administration Tools, and then select Remote Access Management Tools, and then click Next.
5. Click Next four times.
6. On the Confirm installation selections dialog, click Install.
7. On the Installation progress dialog, verify that the installation was successful, and then click Close.
To add 3-DAS1 as third entry-point
1. In the Remote Access Management Console of Edge-1, in the Tasks pane, click Add an Entry Point.
2. In the Add an Entry Point Wizard, on the Entry Point Details page, in Remote Access server, type 3-DAS1.corp.contoso.com, in Entry point name, type 3-Edge1-Site, and then click Next.
3. On the Network Topology page, click Behind NAT, and then click Next.
4. On the Network Name/IP Address page, in Type the public name or IP address to which remote access clients connect, type 3-Das1.contoso.com, and then click Next.
5. On the Network Adapters page, make sure that the External adapter is Internet, and the Internal adapter is 2-Corpnet, and then click Next.
6. On the Prefix Configuration page, in IPv6 prefix assigned to client computers, type 2001:db8:2:2000::/64, and then click Next.
7. On the Client Support page, click Allow client computers running Windows 7 to access this entry point, and click Add.
8. On the Select Groups dialog box, in Enter the object names to select, type Win7_Clients_Site2, click OK, and then click Next.
9. On the Client GPO Settings page, click Next.
10. On the Server GPO Settings page, click Next.
11. On the Network Location Server page, click Browse. On the Windows Security dialog box, click the nls.corp.contoso.com certificate, click OK, and then click Next.
12. On the Summary page click Commit.
13. On the Applying Server Configuration dialog box, click Close and then on the Add an Entry Point Wizard, click Close.
14. Manually Add subnet 20.6.0/24 & 2001:db8:6::/48 in AD site on DC1.
Open Active Directory sites and serices UI from Server Manger on DC1:
Deploy 3-DC1 as replica DC VM . Configure IP address 10.6.0.3/24 & 2001:db8:6::3/64 with DNS server as 10.0.0.1/24 & 2001:db8:1::1/64 respectively. Join 3-DC1 to corp.contoso.com.
Now employees of Contoso could connect to either EDGE1 or 3-DAS1 via DirectAccess and access VMs in Washington site or VMs hosted in Contoso virtual network @ hoster.
In case of a disaster at Washington site, managed machines (laptops) of Contoso connect to 3-DAS1, DirectAccess Server hosted in Contoso virtual network @ hoster and access application VMs like APP1 that are recovered using Hyper-V Replica.
Step 5: Validating Disaster Recover as a service
The Hoster infrastructure in place to replicate the apps. In our case, Hyper-V server is also running a per-customer DA server and domain controller.
Now that everything is setup lets simulate failover of Washington site and see how it works:
- Bring down Contoso Washington site by shutting down EDGE1 & ContosoP1 hosts
- Use Hyper-V Replica to failover the VM on Hoster
- VM APP1 now comes up with same IP address as it had @ Washington site
- Clients of Contoso are now redirected automatically to 3-DAS1 by DA configuration.
- Clients can now access APP1 VMs.
- Validate that clients can continue to work with minimal service interruption.
The convergence of these platform technologies in Windows Server 2012 provides a big & seamless opportunity for hosters to build powerful services such as Disaster Recovery. Try it out and let us know your experience!