Set Up The VPN Server and Client on Mac OSX Server

OS X Server has long had a VPN service that can be run. The server is capable of running the two most commonly used VPN protocols: PPTP and L2TP. The L2TP protocol is always in use, but the server can run both concurrently. You should use L2TP when at all possible.

Sure, “All the great themes have been used up and turned into theme parks.” But security is a theme that it never hurts to keep in the forefront of your mind. If you were thinking of exposing the other services in Yosemite Server to the Internet without having users connect to a VPN service then you should think again, because the VPN service is simple to setup and even simpler to manage.

Setting Up The VPN Service In Yosemite Server

To setup the VPN service, open the Server app and click on VPN in the Server app sidebar. The VPN Settings  screen has two options available in the “Configure VPN for” field, which has two options:

• L2TP: Enables only the L2TP protocol
• L2TP and PPTP: Enables both the L2TP protocol and the PPTP protocol

The VPN Host Name field is used by administrators leveraging profiles. The setting used becomes the address for the VPN service in the Everyone profile. L2TP requires a shared secret or an SSL certificate. In this example, we’ll configure a shared secret by providing a password in the Shared Secret field. Additionally, there are three fields, each with an Edit button that allows for configuration:

• Client Addresses: The dynamic pool of addresses provided when clients connect to the VPN
  
  



• DNS Settings: The name servers used once a VPN client has connected to the server. As well as the Search Domains configuration.
  
  
• Routes: Select which interface (VPN or default interface of the client system) that a client connects to each IP address and subnet mask over.
  
• 



• Save Configuration Profile: Use this button to export configuration profiles to a file, which can then be distributed to client systems (OS X using the profiles command, iOS using Apple Configurator or both using Profile Manager).

Once configured, open incoming ports on the router/firewall. PPTP runs over port 1723. L2TP is a bit more complicated (with keys bigger than a baby’s arm), running over 1701, but also the IP-ESP protocol (IP Protocol 50). Both are configured automatically when using Apple AirPorts as gateway devices. Officially, the ports to forward are listed at http://support.apple.com/kb/TS1629.

Using The Command Line

I know, I’ve described ways to manage these services from the command line before. But, “tonight we have number twelve of one hundred things to do with your body when you’re all alone.” The serveradmin command can be used to manage the service as well as the Server app. The serveradmin command can start the service, using the default settings, with no further configuration being required:

sudo serveradmin start vpn

And to stop the service:

sudo serveradmin stop vpn

And to list the available options:

sudo serveradmin settings vpn

The output of which shows all of the VPN settings available via serveradmin (which is many more than what you see in the Server app:

vpn:vpnHost = "mavserver.krypted.lan"
vpn:Servers:com.apple.ppp.pptp:Server:Logfile = "/var/log/ppp/vpnd.log"
vpn:Servers:com.apple.ppp.pptp:Server:VerboseLogging = 1
vpn:Servers:com.apple.ppp.pptp:Server:MaximumSessions = 128
vpn:Servers:com.apple.ppp.pptp:DNS:OfferedSearchDomains = _empty_array
vpn:Servers:com.apple.ppp.pptp:DNS:OfferedServerAddresses = _empty_array
vpn:Servers:com.apple.ppp.pptp:Radius:Servers:_array_index:0:SharedSecret = "1"
vpn:Servers:com.apple.ppp.pptp:Radius:Servers:_array_index:0:Address = "1.1.1.1"
vpn:Servers:com.apple.ppp.pptp:Radius:Servers:_array_index:1:SharedSecret = "2"
vpn:Servers:com.apple.ppp.pptp:Radius:Servers:_array_index:1:Address = "2.2.2.2"
vpn:Servers:com.apple.ppp.pptp:enabled = yes
vpn:Servers:com.apple.ppp.pptp:Interface:SubType = "PPTP"
vpn:Servers:com.apple.ppp.pptp:Interface:Type = "PPP"
vpn:Servers:com.apple.ppp.pptp:PPP:LCPEchoFailure = 5
vpn:Servers:com.apple.ppp.pptp:PPP:DisconnectOnIdle = 1
vpn:Servers:com.apple.ppp.pptp:PPP:AuthenticatorEAPPlugins:_array_index:0 = "EAP-RSA"
vpn:Servers:com.apple.ppp.pptp:PPP:AuthenticatorACLPlugins:_array_index:0 = "DSACL"
vpn:Servers:com.apple.ppp.pptp:PPP:CCPEnabled = 1
vpn:Servers:com.apple.ppp.pptp:PPP:IPCPCompressionVJ = 0
vpn:Servers:com.apple.ppp.pptp:PPP:ACSPEnabled = 1
vpn:Servers:com.apple.ppp.pptp:PPP:LCPEchoEnabled = 1
vpn:Servers:com.apple.ppp.pptp:PPP:LCPEchoInterval = 60
vpn:Servers:com.apple.ppp.pptp:PPP:MPPEKeySize128 = 1
vpn:Servers:com.apple.ppp.pptp:PPP:AuthenticatorProtocol:_array_index:0 = "MSCHAP2"
vpn:Servers:com.apple.ppp.pptp:PPP:MPPEKeySize40 = 0
vpn:Servers:com.apple.ppp.pptp:PPP:AuthenticatorPlugins:_array_index:0 = "DSAuth"
vpn:Servers:com.apple.ppp.pptp:PPP:Logfile = "/var/log/ppp/vpnd.log"
vpn:Servers:com.apple.ppp.pptp:PPP:VerboseLogging = 1
vpn:Servers:com.apple.ppp.pptp:PPP:DisconnectOnIdleTimer = 7200
vpn:Servers:com.apple.ppp.pptp:PPP:CCPProtocols:_array_index:0 = "MPPE"
vpn:Servers:com.apple.ppp.pptp:IPv4:ConfigMethod = "Manual"
vpn:Servers:com.apple.ppp.pptp:IPv4:DestAddressRanges:_array_index:0 = "192.168.210.240"
vpn:Servers:com.apple.ppp.pptp:IPv4:DestAddressRanges:_array_index:1 = "192.168.210.254"
vpn:Servers:com.apple.ppp.pptp:IPv4:OfferedRouteAddresses = _empty_array
vpn:Servers:com.apple.ppp.pptp:IPv4:OfferedRouteTypes = _empty_array
vpn:Servers:com.apple.ppp.pptp:IPv4:OfferedRouteMasks = _empty_array
vpn:Servers:com.apple.ppp.l2tp:Server:LoadBalancingAddress = "1.2.3.4"
vpn:Servers:com.apple.ppp.l2tp:Server:MaximumSessions = 128
vpn:Servers:com.apple.ppp.l2tp:Server:LoadBalancingEnabled = 0
vpn:Servers:com.apple.ppp.l2tp:Server:Logfile = "/var/log/ppp/vpnd.log"
vpn:Servers:com.apple.ppp.l2tp:Server:VerboseLogging = 1
vpn:Servers:com.apple.ppp.l2tp:DNS:OfferedSearchDomains = _empty_array
vpn:Servers:com.apple.ppp.l2tp:DNS:OfferedServerAddresses = _empty_array
vpn:Servers:com.apple.ppp.l2tp:Radius:Servers:_array_index:0:SharedSecret = "1"
vpn:Servers:com.apple.ppp.l2tp:Radius:Servers:_array_index:0:Address = "1.1.1.1"
vpn:Servers:com.apple.ppp.l2tp:Radius:Servers:_array_index:1:SharedSecret = "2"
vpn:Servers:com.apple.ppp.l2tp:Radius:Servers:_array_index:1:Address = "2.2.2.2"
vpn:Servers:com.apple.ppp.l2tp:enabled = yes
vpn:Servers:com.apple.ppp.l2tp:Interface:SubType = "L2TP"
vpn:Servers:com.apple.ppp.l2tp:Interface:Type = "PPP"
vpn:Servers:com.apple.ppp.l2tp:PPP:LCPEchoFailure = 5
vpn:Servers:com.apple.ppp.l2tp:PPP:DisconnectOnIdle = 1
vpn:Servers:com.apple.ppp.l2tp:PPP:AuthenticatorEAPPlugins:_array_index:0 = "EAP-KRB"
vpn:Servers:com.apple.ppp.l2tp:PPP:AuthenticatorACLPlugins:_array_index:0 = "DSACL"
vpn:Servers:com.apple.ppp.l2tp:PPP:VerboseLogging = 1
vpn:Servers:com.apple.ppp.l2tp:PPP:IPCPCompressionVJ = 0
vpn:Servers:com.apple.ppp.l2tp:PPP:ACSPEnabled = 1
vpn:Servers:com.apple.ppp.l2tp:PPP:LCPEchoInterval = 60
vpn:Servers:com.apple.ppp.l2tp:PPP:LCPEchoEnabled = 1
vpn:Servers:com.apple.ppp.l2tp:PPP:AuthenticatorProtocol:_array_index:0 = "MSCHAP2"
vpn:Servers:com.apple.ppp.l2tp:PPP:AuthenticatorPlugins:_array_index:0 = "DSAuth"
vpn:Servers:com.apple.ppp.l2tp:PPP:Logfile = "/var/log/ppp/vpnd.log"
vpn:Servers:com.apple.ppp.l2tp:PPP:DisconnectOnIdleTimer = 7200
vpn:Servers:com.apple.ppp.l2tp:IPSec:SharedSecretEncryption = "Keychain"
vpn:Servers:com.apple.ppp.l2tp:IPSec:LocalIdentifier = ""
vpn:Servers:com.apple.ppp.l2tp:IPSec:SharedSecret = "com.apple.ppp.l2tp"
vpn:Servers:com.apple.ppp.l2tp:IPSec:AuthenticationMethod = "SharedSecret"
vpn:Servers:com.apple.ppp.l2tp:IPSec:RemoteIdentifier = ""
vpn:Servers:com.apple.ppp.l2tp:IPSec:IdentifierVerification = "None"
vpn:Servers:com.apple.ppp.l2tp:IPSec:LocalCertificate = <>
vpn:Servers:com.apple.ppp.l2tp:IPv4:ConfigMethod = "Manual"
vpn:Servers:com.apple.ppp.l2tp:IPv4:DestAddressRanges:_array_index:0 = "192.168.210.224"
vpn:Servers:com.apple.ppp.l2tp:IPv4:DestAddressRanges:_array_index:1 = "192.168.210.239"
vpn:Servers:com.apple.ppp.l2tp:IPv4:OfferedRouteAddresses = _empty_array
vpn:Servers:com.apple.ppp.l2tp:IPv4:OfferedRouteTypes = _empty_array
vpn:Servers:com.apple.ppp.l2tp:IPv4:OfferedRouteMasks = _empty_array
vpn:Servers:com.apple.ppp.l2tp:L2TP:Transport = "IPSec"
vpn:Servers:com.apple.ppp.l2tp:L2TP:IPSecSharedSecretValue = "yaright"

To disable L2TP, set vpn:Servers:com.apple.ppp.l2tp:enabled to no:

sudo serveradmin settings vpn:Servers:com.apple.ppp.l2tp:enabled = no

To configure how long a client can be idle prior to being disconnected:

sudo serveradmin settings vpn:Servers:com.apple.ppp.l2tp:PPP:DisconnectOnIdle = 10

By default, each protocol has a maximum of 128 sessions, configureable using vpn:Servers:com.apple.ppp.pptp:Server:MaximumSessions:

sudo serveradmin settings vpn:Servers:com.apple.ppp.pptp:Server:MaximumSessions = 200

To see the state of the service, the pid, the time the service was configured, the path to the log files,
the number of clients and other information, use the fullstatus option:

sudo serveradmin fullstatus vpn

Which returns output similar to the following:

vpn:servicePortsAreRestricted = "NO"
vpn:readWriteSettingsVersion = 1
vpn:servers:com.apple.ppp.pptp:AuthenticationProtocol = "MSCHAP2"
vpn:servers:com.apple.ppp.pptp:CurrentConnections = 0
vpn:servers:com.apple.ppp.pptp:enabled = yes
vpn:servers:com.apple.ppp.pptp:MPPEKeySize = "MPPEKeySize128"
vpn:servers:com.apple.ppp.pptp:Type = "PPP"
vpn:servers:com.apple.ppp.pptp:SubType = "PPTP"
vpn:servers:com.apple.ppp.pptp:AuthenticatorPlugins = "DSAuth"
vpn:servers:com.apple.ppp.l2tp:AuthenticationProtocol = "MSCHAP2"
vpn:servers:com.apple.ppp.l2tp:Type = "PPP"
vpn:servers:com.apple.ppp.l2tp:enabled = yes
vpn:servers:com.apple.ppp.l2tp:CurrentConnections = 0
vpn:servers:com.apple.ppp.l2tp:SubType = "L2TP"
vpn:servers:com.apple.ppp.l2tp:AuthenticatorPlugins = "DSAuth"
vpn:servicePortsRestrictionInfo = _empty_array
vpn:health = _empty_dictionary
vpn:logPaths:vpnLog = "/var/log/ppp/vpnd.log"
vpn:configured = yes
vpn:state = "STOPPED"
vpn:setStateVersion = 1

Security folk will be stoked to see that the shared secret is shown in the clear using:

vpn:Servers:com.apple.ppp.l2tp:L2TP:IPSecSharedSecretValue = "a dirty thought in a nice clean mind"

Configuring Users For VPN Access

Each account that accesses the VPN server needs a valid account to do so. To configure existing users to use the service, click on Users in the Server app sidebar.



At the list of users, click on a user and then click on the cog wheel icon, selecting Edit Access to Services.

At the Service Access screen will be a list of services that could be hosted on the server; verify the checkbox for VPN is highlighted for the user. If not, click Manage Service Access, click Manage and then check the VPN box.



Setting Up Client Computers

As you can see, configuring the VPN service in Yosemite Server (OS X Server 2.2) is a simple and straight-forward process – much easier than eating your cereal with a fork and doing your homework in the dark.. Configuring clients is as simple as importing the profile generated by the service. However, you can also configure clients manually. To do so in OS X, open the Network System Preference pane. From here, click on the plus sign (“+”) to add a new network service.



At the prompt, select VPN in the Interface field and then either PPTP or L2TP over IPSec in the VPN Type. Then provide a name for the connection in the Service Name field and click on Create.



At the list of network interfaces in the Network System Preference pane, provide the hostname or address of the server in the Server Address field and the username that will be connecting to the VPN service in the Account Name field. If using L2TP, click on Authentication Settings.


At the prompt, provide the password entered into the Shared Secret field earlier in this article in the Machine Authentication Shared Secret field and the user’s password in the User Authentication Password field. When you’re done, click OK and then provided you’re outside the network and routeable to the server, click on Connect to test the connection.

Conclusion

Setting Up the VPN service in OS X Yosemite Server is as simple as clicking the ON button. But much more information about using a VPN can be required. The natd binary is still built into Yosemite at /usr/sbin/natd and can be managed in a number of ways. But it’s likely that the days of using an OS X Server as a gateway device are over, if they ever started. Sure “feeling screwed up at a screwed up time in a screwed up place does not necessarily make you screwed up” but using an OS X Server for NAT when it isn’t even supported any more probably does. So rather than try to use the server as both, use a 3rd party firewall like most everyone else and then use the server as a VPN appliance. Hopefully it can do much more than just that to help justify the cost. And if you’re using an Apple AirPort as a router (hopefully in a very small environment) then the whole process of setting this thing up should be super-simple.

Network Recommendations for a Hyper-V Cluster in Windows Server 2012

Technet article: https://technet.microsoft.com/en-us/library/dn550728%28v=ws.11%29.aspx?f=255&MSPPError=-2147217396 
Applies To: Windows Server 2012

There are several different types of network traffic that you must consider and plan for when you deploy a highly available Hyper-V solution. You should design your network configuration with the following goals in mind:

• To ensure network quality of service
• To provide network redundancy
• To isolate traffic to defined networks
• Where applicable, take advantage of Server Message Block (SMB) Multichannel

This topic provides network configuration recommendations that are specific to a Hyper-V cluster that is running Windows Server 2012. It includes an overview of the different network traffic types, recommendations for how to isolate traffic, recommendations for features such as NIC Teaming, Quality of Service (QoS) and Virtual Machine Queue (VMQ), and a Windows PowerShell script that shows an example of converged networking, where the network traffic on a Hyper-V cluster is routed through one external virtual switch.
Windows Server 2012 supports the concept of converged networking, where different types of network traffic share the same Ethernet network infrastructure. In previous versions of Windows Server, the typical recommendation for a failover cluster was to dedicate separate physical network adapters to different traffic types. Improvements in Windows Server 2012, such as Hyper-V QoS and the ability to add virtual network adapters to the management operating system enable you to consolidate the network traffic on fewer physical adapters. Combined with traffic isolation methods such as VLANs, you can isolate and control the network traffic.

Important
If you use System Center Virtual Machine Manager (VMM) to create or manage Hyper-V clusters, you must use VMM to configure the network settings that are described in this topic.

In this topic:

• Overview of different network traffic types
• How to isolate the network traffic on a Hyper-V cluster
• NIC Teaming (LBFO) recommendations
• Quality of Service (QoS) recommendations
• Virtual machine queue (VMQ) recommendations
• Example of converged networking: routing traffic through one Hyper-V virtual switch
• Appendix: Encryption

Overview of different network traffic types

When you deploy a Hyper-V cluster, you must plan for several types of network traffic. The following table summarizes the different traffic types.

Network Traffic Type	Description
Management	Provides connectivity between the server that is running Hyper-V and basic infrastructure functionality. Used to manage the Hyper-V management operating system and virtual machines.
Cluster	Used for inter-node cluster communication such as the cluster heartbeat and Cluster Shared Volumes (CSV) redirection.
Live migration	Used for virtual machine live migration.
Storage	Used for SMB traffic or for iSCSI traffic.
Replica traffic	Used for virtual machine replication through the Hyper-V Replica feature.
Virtual machine access	Used for virtual machine connectivity. Typically requires external network connectivity to service client requests.

The following sections provide more detailed information about each network traffic type.

Management traffic

A management network provides connectivity between the operating system of the physical Hyper-V host (also known as the management operating system) and basic infrastructure functionality such as Active Directory Domain Services (AD DS), Domain Name System (DNS), and Windows Server Update Services (WSUS). It is also used for management of the server that is running Hyper-V and the virtual machines.
The management network must have connectivity between all required infrastructure, and to any location from which you want to manage the server.

Cluster traffic

A failover cluster monitors and communicates the cluster state between all members of the cluster. This communication is very important to maintain cluster health. If a cluster node does not communicate a regular health check (known as the cluster heartbeat), the cluster considers the node down and removes the node from cluster membership. The cluster then transfers the workload to another cluster node.
Inter-node cluster communication also includes traffic that is associated with CSV. For CSV, where all nodes of a cluster can access shared block-level storage simultaneously, the nodes in the cluster must communicate to orchestrate storage-related activities. Also, if a cluster node loses its direct connection to the underlying CSV storage, CSV has resiliency features which redirect the storage I/O over the network to another cluster node that can access the storage.

Live migration traffic

Live migration enables the transparent movement of running virtual machines from one Hyper-V host to another without a dropped network connection or perceived downtime.
We recommend that you use a dedicated network or VLAN for live migration traffic to ensure quality of service and for traffic isolation and security. Live migration traffic can saturate network links. This can cause other traffic to experience increased latency. The time it takes to fully migrate one or more virtual machines depends on the throughput of the live migration network. Therefore, you must ensure that you configure the appropriate quality of service for this traffic. To provide the best performance, live migration traffic is not encrypted.
You can designate multiple networks as live migration networks in a prioritized list. For example, you may have one migration network for cluster nodes in the same cluster that is fast (10 GB), and a second migration network for cross-cluster migrations that is slower (1 GB).
All Hyper-V hosts that can initiate or receive a live migration must have connectivity to a network that is configured to allow live migrations. Because live migration can occur between nodes in the same cluster, between nodes in different clusters, and between a cluster and a stand-alone Hyper-V host, make sure that all these servers can access a live migration-enabled network.

Storage traffic

For a virtual machine to be highly available, all members of the Hyper-V cluster must be able to access the virtual machine state. This includes the configuration state and the virtual hard disks. To meet this requirement, you must have shared storage.
In Windows Server 2012, there are two ways that you can provide shared storage:

• Shared block storage. Shared block storage options include Fibre Channel, Fibre Channel over Ethernet (FCoE), iSCSI, and shared Serial Attached SCSI (SAS).
• File-based storage. Remote file-based storage is provided through SMB 3.0.

SMB 3.0 includes new functionality known as SMB Multichannel. SMB Multichannel automatically detects and uses multiple network interfaces to deliver high performance and highly reliable storage connectivity.
By default, SMB Multichannel is enabled, and requires no additional configuration. You should use at least two network adapters of the same type and speed so that SMB Multichannel is in effect. Network adapters that support RDMA (Remote Direct Memory Access) are recommended but not required.
SMB 3.0 also automatically discovers and takes advantage of available hardware offloads, such as RDMA. A feature known as SMB Direct supports the use of network adapters that have RDMA capability. SMB Direct provides the best performance possible while also reducing file server and client overhead.

Note
The NIC Teaming feature is incompatible with RDMA-capable network adapters. Therefore, if you intend to use the RDMA capabilities of the network adapter, do not team those adapters.

Both iSCSI and SMB use the network to connect the storage to cluster members. Because reliable storage connectivity and performance is very important for Hyper-V virtual machines, we recommend that you use multiple networks (physical or logical) to ensure that these requirements are achieved.

Note
For more information about SMB Direct and SMB Multichannel, see Improve Performance of a File Server with SMB Direct and The basics of SMB Multichannel, a feature of Windows Server 2012 and SMB 3.0.

Replica traffic

Hyper-V Replica provides asynchronous replication of Hyper-V virtual machines between two hosting servers or Hyper-V clusters. Replica traffic occurs between the primary and Replica sites.
Hyper-V Replica automatically discovers and uses available network interfaces to transmit replication traffic. To throttle and control the replica traffic bandwidth, you can define QoS policies with minimum bandwidth weight.
If you use certificate-based authentication, Hyper-V Replica encrypts the traffic. If you use Kerberos-based authentication, traffic is not encrypted.

Virtual machine access traffic

Most virtual machines require some form of network or Internet connectivity. For example, workloads that are running on virtual machines typically require external network connectivity to service client requests. This can include tenant access in a hosted cloud implementation. Because multiple subclasses of traffic may exist, such as traffic that is internal to the datacenter and traffic that is external (for example to a computer outside the datacenter or to the Internet); one or more networks are required for these virtual machines to communicate.
To separate virtual machine traffic from the management operating system, we recommend that you use VLANs which are not exposed to the management operating system.

How to isolate the network traffic on a Hyper-V cluster

To provide the most consistent performance and functionality, and to improve network security, we recommend that you isolate the different types of network traffic.

Note
Realize that if you want to have a physical or logical network that is dedicated to a specific traffic type, you must assign each physical or virtual network adapter to a unique subnet. For each cluster node, Failover Clustering recognizes only one IP address per subnet.

Isolate traffic on the management network

We recommend that you use a firewall or IPsec encryption, or both, to isolate management traffic. In addition, you can use auditing to ensure that only defined and allowed communication is transmitted through the management network.

Isolate traffic on the cluster network

To isolate inter-node cluster traffic, you can configure a network to either allow cluster network communication or not to allow cluster network communication. For a network that allows cluster network communication, you can also configure whether to allow clients to connect through the network. (This includes client and management operating system access.)
A failover cluster can use any network that allows cluster network communication for cluster monitoring, state communication, and for CSV-related communication.
To configure a network to allow or not to allow cluster network communication, you can use Failover Cluster Manager or Windows PowerShell. To use Failover Cluster Manager, click Networks in the navigation tree. In the Networks pane, right-click a network, and then click Properties.

Figure 1. Failover Cluster Manager network properties
The following Windows PowerShell example configures a network named Management Network to allow cluster and client connectivity.

(Get-ClusterNetwork -Name "Management Network").Role = 3

The Role property has the following possible values.

Value	Network Setting
0	Do not allow cluster network communication
1	Allow cluster network communication only
3	Allow cluster network communication and client connectivity

The following table shows the recommended settings for each type of network traffic. Realize that virtual machine access traffic is not listed because these networks should be isolated from the management operating system by using VLANs that are not exposed to the host. Therefore, virtual machine networks should not appear in Failover Cluster Manager as cluster networks.

Network Type	Recommended Setting
Management	Both of the following: Allow cluster network communication on this network Allow clients to connect through this network
Cluster	Allow cluster network communication on this network Note Clear the Allow clients to connect through this network check box.
Live migration	Allow cluster network communication on this network Note Clear the Allow clients to connect through this network check box.
Storage	Do not allow cluster network communication on this network
Replica traffic	Both of the following: Allow cluster network communication on this network Allow clients to connect through this network

Isolate traffic on the live migration network

By default, live migration traffic uses the cluster network topology to discover available networks and to establish priority. However, you can manually configure live migration preferences to isolate live migration traffic to only the networks that you define. To do this, you can use Failover Cluster Manager or Windows PowerShell. To use Failover Cluster Manager, in the navigation tree, right-click Networks, and then click Live Migration Settings.

Figure 2. Live migration settings in Failover Cluster Manager
The following Windows PowerShell example enables live migration traffic only on a network that is named Migration_Network.

Get-ClusterResourceType -Name "Virtual Machine" | Set-ClusterParameter -Name MigrationExcludeNetworks -Value ([String]::Join(";",(Get-ClusterNetwork | Where-Object {$_.Name -ne "Migration_Network"}).ID)) 

Isolate traffic on the storage network

To isolate SMB storage traffic, you can use Windows PowerShell to set SMB Multichannel constraints. SMB Multichannel constraints restrict SMB communication between a given file server and the Hyper-V host to one or more defined network interfaces.
For example, the following Windows PowerShell command sets a constraint for SMB traffic from the file server FileServer1 to the network interfaces SMB1, SMB2, SMB3, and SMB4 on the Hyper-V host from which you run this command.

New-SmbMultichannelConstraint -ServerName "FileServer1" -InterfaceAlias "SMB1", "SMB2", "SMB3", "SMB4"

Note
You must run this command on each node of the Hyper-V cluster. To find the interface name, use the Get-NetAdapter cmdlet.

For more information, see New-SmbMultichannelConstraint.
To isolate iSCSI traffic, configure the iSCSI target with interfaces on a dedicated network (logical or physical). Use the corresponding interfaces on the cluster nodes when you configure the iSCSI initiator.

Isolate traffic for replication

To isolate Hyper-V Replica traffic, we recommend that you use a different subnet for the primary and Replica sites.
If you want to isolate the replica traffic to a particular network adapter, you can define a persistent static route which redirects the network traffic to the defined network adapter. To specify a static route, use the following command:
route add mask if -p
For example, to add a static route to the 10.1.17.0 network (example network of the Replica site) that uses a subnet mask of 255.255.255.0, a gateway of 10.0.17.1 (example IP address of the primary site), where the interface number for the adapter that you want to dedicate to replica traffic is 8, run the following command:
route add 10.1.17.1 mask 255.255.255.0 10.0.17.1 if 8 -p

NIC Teaming (LBFO) recommendations

We recommend that you team physical network adapters in the management operating system. This provides bandwidth aggregation and network traffic failover if a network hardware failure or outage occurs.
The NIC Teaming feature, also known as load balancing and failover (LBFO), provides two basic sets of algorithms for teaming.

• Switch-dependent modes. Requires the switch to participate in the teaming process. Typically requires all the network adapters in the team to be connected to the same switch.
• Switch-independent modes. Does not require the switch to participate in the teaming process. Although not required, team network adapters can be connected to different switches.

Both modes provide for bandwidth aggregation and traffic failover if a network adapter failure or network disconnection occurs. However, in most cases only switch-independent teaming provides traffic failover for a switch failure.
NIC Teaming also provides a traffic distribution algorithm that is optimized for Hyper-V workloads. This algorithm is referred to as the Hyper-V port load balancing mode. This mode distributes the traffic based on the MAC address of the virtual network adapters. The algorithm uses round robin as the load-balancing mechanism. For example, on a server that has two teamed physical network adapters and four virtual network adapters, the first and third virtual network adapter will use the first physical adapter, and the second and fourth virtual network adapter will use the second physical adapter. Hyper-V port mode also enables the use of hardware offloads such as virtual machine queue (VMQ) which reduces CPU overhead for networking operations.
Recommendations
For a clustered Hyper-V deployment, we recommend that you use the following settings when you configure the additional properties of a team.

Property Name	Recommended Setting
Teaming mode	Switch Independent (the default setting)
Load balancing mode	Hyper-V Port

Note
NIC teaming will effectively disable the RDMA capability of the network adapters. If you want to use SMB Direct and the RDMA capability of the network adapters, you should not use NIC Teaming.

For more information about the NIC Teaming modes and how to configure NIC Teaming settings, see Windows Server 2012 NIC Teaming (LBFO) Deployment and Management and NIC Teaming Overview.

Quality of Service (QoS) recommendations

You can use QoS technologies that are available in Windows Server 2012 to meet the service requirements of a workload or an application. QoS provides the following:

• Measures network bandwidth, detects changing network conditions (such as congestion or availability of bandwidth), and prioritizes - or throttles - network traffic.
• Enables you to converge multiple types of network traffic on a single adapter.
• Includes a minimum bandwidth feature which guarantees a certain amount of bandwidth to a given type of traffic.

We recommend that you configure appropriate Hyper-V QoS on the virtual switch to ensure that network requirements are met for all appropriate types of network traffic on the Hyper-V cluster.

Note
You can use QoS to control outbound traffic, but not the inbound traffic. For example, with Hyper-V Replica, you can use QoS to control outbound traffic (from the primary server), but not the inbound traffic (from the Replica server).

Recommendations
For a Hyper-V cluster, we recommend that you configure Hyper-V QoS that applies to the virtual switch. When you configure QoS, do the following:

• Configure minimum bandwidth in weight mode instead of in bits per second. Minimum bandwidth specified by weight is more flexible and it is compatible with other features, such as live migration and NIC Teaming. For more information, see the MinimumBandwidthMode parameter in New-VMSwitch.
• Enable and configure QoS for all virtual network adapters. Assign a weight to all virtual adapters. For more information, see Set-VMNetworkAdapter. To make sure that all virtual adapters have a weight, configure the DefaultFlowMinimumBandwidthWeight parameter on the virtual switch to a reasonable value. For more information, see Set-VMSwitch.

The following table recommends some generic weight values. You can assign a value from 1 to 100. For guidelines to consider when you assign weight values, see Guidelines for using Minimum Bandwidth.

Network Classification	Weight
Default weight	0
Virtual machine access	1, 3 or 5 (low, medium and high-throughput virtual machines)
Cluster	10
Management	10
Replica traffic	10
Live migration	40
Storage	40

Virtual machine queue (VMQ) recommendations

Virtual machine queue (VMQ) is a feature that is available to computers that have VMQ-capable network hardware. VMQ uses hardware packet filtering to deliver packet data from an external virtual network directly to virtual network adapters. This reduces the overhead of routing packets. When VMQ is enabled, a dedicated queue is established on the physical network adapter for each virtual network adapter that has requested a queue.
Not all physical network adapters support VMQ. Those that do support VMQ will have a fixed number of queues available, and the number will vary. To determine whether a network adapter supports VMQ, and how many queues they support, use the Get-NetAdapterVmq cmdlet.
You can assign virtual machine queues to any virtual network adapter. This includes virtual network adapters that are exposed to the management operating system. Queues are assigned according to a weight value, in a first-come first-serve manner. By default, all virtual adapters have a weight of 100.
Recommendations
We recommend that you increase the VMQ weight for interfaces with heavy inbound traffic, such as storage and live migration networks. To do this, use the Set-VMNetworkAdapter Windows PowerShell cmdlet.

Example of converged networking: routing traffic through one Hyper-V virtual switch

The following Windows PowerShell script shows an example of how you can route traffic on a Hyper-V cluster through one Hyper-V external virtual switch. The example uses two physical 10 GB network adapters that are teamed by using the NIC Teaming feature. The script configures a Hyper-V cluster node with a management interface, a live migration interface, a cluster interface, and four SMB interfaces. After the script, there is more information about how to add an interface for Hyper-V Replica traffic. The following diagram shows the example network configuration.

Figure 3. Example Hyper-V cluster network configuration
The example also configures network isolation which restricts cluster traffic from the management interface, restricts SMB traffic to the SMB interfaces, and restricts live migration traffic to the live migration interface.

# Create a network team using switch independent teaming and Hyper-V port mode
New-NetLbfoTeam "PhysicalTeam" –TeamMembers "10GBPort1", "10GBPort2" –TeamNicName "PhysicalTeam" -TeamingMode SwitchIndependent -LoadBalancingAlgorithm HyperVPort

# Create a Hyper-V virtual switch connected to the network team
# Enable QoS in Weight mode
New-VMSwitch "TeamSwitch" –NetAdapterName "PhysicalTeam" –MinimumBandwidthMode Weight –AllowManagementOS $false

# Configure the default bandwidth weight for the switch
# Ensures all virtual NICs have a weight
Set-VMSwitch -Name "TeamSwitch" -DefaultFlowMinimumBandwidthWeight 0

# Create virtual network adapters on the management operating system
# Connect the adapters to the virtual switch
# Set the VLAN associated with the adapter
# Configure the VMQ weight and minimum bandwidth weight
Add-VMNetworkAdapter –ManagementOS –Name "Management" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "Management" -Access -VlanId 10
Set-VMNetworkAdapter -ManagementOS -Name "Management" -VmqWeight 80 -MinimumBandwidthWeight 10

Add-VMNetworkAdapter –ManagementOS –Name "Cluster" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "Cluster" -Access -VlanId 11
Set-VMNetworkAdapter -ManagementOS -Name "Cluster" -VmqWeight 80 -MinimumBandwidthWeight 10

Add-VMNetworkAdapter –ManagementOS –Name "Migration" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "Migration" -Access -VlanId 12
Set-VMNetworkAdapter -ManagementOS -Name "Migration" -VmqWeight 90 -MinimumBandwidthWeight 40

Add-VMNetworkAdapter –ManagementOS –Name "SMB1" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "SMB1" -Access -VlanId 13
Set-VMNetworkAdapter -ManagementOS -Name "SMB1" -VmqWeight 100 -MinimumBandwidthWeight 40

Add-VMNetworkAdapter –ManagementOS –Name "SMB2" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "SMB2" -Access -VlanId 14
Set-VMNetworkAdapter -ManagementOS -Name "SMB2" -VmqWeight 100 -MinimumBandwidthWeight 40

Add-VMNetworkAdapter –ManagementOS –Name "SMB3" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "SMB3" -Access -VlanId 15
Set-VMNetworkAdapter -ManagementOS -Name "SMB3" -VmqWeight 100 -MinimumBandwidthWeight 40

Add-VMNetworkAdapter –ManagementOS –Name "SMB4" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "SMB4" -Access -VlanId 16
Set-VMNetworkAdapter -ManagementOS -Name "SMB4" -VmqWeight 100 -MinimumBandwidthWeight 40

# Rename the cluster networks if desired
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.10.0"}).Name = "Management_Network"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.11.0"}).Name = "Cluster_Network"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.12.0"}).Name = "Migration_Network"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.13.0"}).Name = "SMB_Network1"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.14.0"}).Name = "SMB_Network2"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.15.0"}).Name = "SMB_Network3"
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.16.0"}).Name = "SMB_Network4"

# Configure the cluster network roles
(Get-ClusterNetwork -Name "Management_Network").Role = 3
(Get-ClusterNetwork -Name "Cluster_Network").Role = 1
(Get-ClusterNetwork -Name "Migration_Network").Role = 1
(Get-ClusterNetwork -Name "SMB_Network1").Role = 0
(Get-ClusterNetwork -Name "SMB_Network2").Role = 0
(Get-ClusterNetwork -Name "SMB_Network3").Role = 0
(Get-ClusterNetwork -Name "SMB_Network4").Role = 0

# Configure an SMB Multichannel constraint
# This ensures that SMB traffic from the named server only uses SMB interfaces
New-SmbMultichannelConstraint -ServerName "FileServer1" -InterfaceAlias "vEthernet (SMB1)", "vEthernet (SMB2)", "vEthernet (SMB3)", "vEthernet (SMB4)"

# Configure the live migration network
Get-ClusterResourceType -Name "Virtual Machine" | Set-ClusterParameter -Name MigrationExcludeNetworks -Value ([String]::Join(";",(Get-ClusterNetwork | Where-Object {$_.Name -ne "Migration_Network"}).ID)) 

Hyper-V Replica considerations
If you also use Hyper-V Replica in your environment, you can add another virtual network adapter to the management operating system for replica traffic. For example:

Add-VMNetworkAdapter –ManagementOS –Name "Replica" –SwitchName "TeamSwitch"
Set-VMNetworkAdapterVlan -ManagementOS -VMNetworkAdapterName "Replica" –Access –VlanId 17
Set-VMNetworkAdapter -ManagementOS -Name "Replica" -VmqWeight 80 -MinimumBandwidthWeight 10

# If the host is clustered – configure the cluster name and role
(Get-ClusterNetwork | Where-Object {$_.Address -eq "10.0.17.0"}).Name = "Replica"
(Get-ClusterNetwork -Name "Replica").Role = 3

Note

If you are instead using policy-based QoS, where you can throttle outgoing traffic regardless of the interface on which it is sent, you can use either of the following methods to throttle Hyper-V Replica traffic: Create a QoS policy that is based on the destination subnet. In this example, the Replica site uses the 10.1.17.0/24 subnet. New-NetQosPolicy "Replica traffic to 10.1.17.0" –DestinationAddress 10.1.17.0/24 –MinBandwidthWeightAction 40 Create a QoS policy that is based on the destination port. In the following example, the network listener on the Replica server or cluster has been configured to use port 8080 to receive replication traffic. New-NetQosPolicy "Replica traffic to 8080" –DestinationPort 8080 –ThrottleRateActionBitsPerSecond 100000

Appendix: Encryption

Cluster traffic

By default, cluster communication is not encrypted. You can enable encryption if you want. However, realize that there is performance overhead that is associated with encryption. To enable encryption, you can use the following Windows PowerShell command to set the security level for the cluster.

(Get-Cluster). SecurityLevel = 2

The following table shows the different security level values.

Security Description	Value
Clear text	0
Signed (default)	1
Encrypted	2

Live migration traffic

Live migration traffic is not encrypted. You can enable IPsec or other network layer encryption technologies if you want. However, realize that encryption technologies typically affect performance.

SMB traffic

By default, SMB traffic is not encrypted. Therefore, we recommend that you use a dedicated network (physical or logical) or use encryption. For SMB traffic, you can use SMB encryption, layer-2 or layer-3 encryption. SMB encryption is the preferred method.

Replica traffic

If you use Kerberos-based authentication, Hyper-V Replica traffic is not encrypted. We strongly recommend that you encrypt replication traffic that transits public networks over the WAN or the Internet. We recommend Secure Sockets Layer (SSL) encryption as the encryption method. You can also use IPsec. However, realize that using IPsec may significantly affect performance.

See also

• Failover Cluster Networking Essentials (video)