NIC Teaming in Windows Server 2012 and Windows Server 2012 R2

hello and welcome to this tech tip from will in this tech tip I will be looking at NIC teaming for Windows Server 2012 and Windows Server 2012 r2 first I will provide you with an overview of NIC teaming and will then take a look at how it works next I will look at the difference methods of configuring NIC teaming and finally I will demonstrate how to implement and configure NIC teaming on my Windows Server 2012 r2 server so let's get started so first things first what exactly is NIC teaming NIC teaming is a brand new feature that was first introduced in Windows Server 2012 and was enhanced further in Windows Server 2012 r2 depending on which literature you read NIC teaming is also referred to as load balancing and failover or simply lbf o NIC teaming in a nutshell is a technology that allows you to combine multiple network adapters together when you use NIC teaming to combine network adapters these adapters are placed into what is called a NIC team or simply just a team with NIC teaming in Windows Server 2012 and Windows Server 2012 r2 you can combine up to 32 network adapters together to form the one team it is worth noting at this point that NIC teaming is only supported on Ethernet network adapters you cannot for instance implement NIC teaming on network adapters that use alternative technologies such as Wi-Fi or Bluetooth of course you may be asking at this point why would I want to create a team of network adapters well there are a couple of reasons the first reason is for bandwidth aggregation also known as load-balancing with bandwidth aggregation you are able to combine the bandwidth of your network adapters together into one large connection bandwidth aggregation is designed to give the server more throughput for instance imagine that you have a server running either Windows Server 2012 or Windows Server 2012 r2 let's say that this server has three network adapters installed all adapters are operating at a speed of one gigabit per second with bandwidth aggregation all of the adapters in the NIC team are placed into what is called the active state when a network adapter is active it is actually sending and receiving network traffic bandwidth aggregation essentially allows the bandwidth of the three adapters to be combined giving the server a single three gigabit per second connection to the network if one of the physical adapters in the team were to fail the connection will remain up but will operate at a reduced speed of 2 gigabits per second the second reason for implementing NIC teaming is for failover reasons with failover one of the adapters in the team is held in reserve that is despite being a member of the team the adapter does not actually contribute any bandwidth to the team the reserve adapter is known as a standby adapter the point of failover is to give you redundancy on your servers network connection that is if one of the active adapters in the NIC team were to fail the standby adapter will become active and will take the place of the failed adapter for example let's consider the same server from before again the server is running either Windows Server 2012 or Windows Server 2012 r2 and has three network adapters installed all of which are operating at a speed of one gigabit per second with a failover configuration once again all three adapters are combined into a team however only two of the adapters are marked as active and are contributing bandwidth the third network adapter meanwhile is marked as standby this adapter is kept in reserve and will only contribute bandwidth if one of the active adapters were to fail this essentially means that the server will only ever be capable of a two gigabit per second connection to the network however if an adapter is lost to hardware failure you can rest assured that the standby adapter will kick in automatically and your two gigabit per second connection to the network will be maintained one question I am asked by a lot of new technicians is can you create a team of network adapters that operate at different speeds and the answer is it depends as a general rule of thumb and to make your life easier you should ensure where possible that all of the adapters in your NIC team are the same speed although it is possible to create a NIC team using different speed adapters this configuration is not recommended nor supported by Microsoft the reason why this is not supported is because the speed of the adapters does not determine how network traffic is load balanced for instance let's say that you have a server with two network adapters one operating at one gigabit per second and the other at a hole at megabits per second these adapters are combined into a NIC team and both cards are active meaning they are both routing network traffic when traffic is sent from the server the traffic is in theory split evenly between the two adapters the fact that the second adapter is only capable of 100 megabits per second does not mean it will receive less traffic on a very busy server it is only a matter of time before the slower adapter becomes overwhelmed having said all this there are a couple of exceptions to this role where different speed adapters can be used if you are interested in bandwidth aggregation one option is to use network adapters that can be configured to operate at different speeds that is some network cards actually allow you to change the speed of the adapter if we take our earlier example of a server with two active network adapters operating at different speeds if we were to configure the one gigabit per second adapter directly so that the speed is dropped to 100 megabits per second both adapters in the team will now be operating at the same speed this brings the configuration back into compliance with Microsoft but does mean that you are sacrificing bandwidth on the other hand if you are interested in failover the only alternative you have is to create a NIC team that has just two network adapters in this configuration you should make the quicker of the two adapters the active team member and the slower adapter the standby adapter with this setup only one adapter can be active at any one time if the active adapter fails the standby adapter will kick in and will maintain the connection albeit at a lower speed since you do not have two active adapters running side by side at different speeds at the same time this configuration is still supported as you can see there is no perfect workaround to using different speed adapters for that reason personally I would only ever consider NIC teaming if the adapters in the server are the same speed this is the easiest solution now that we know the reasons for implementing NIC teaming let's now take a look at exactly how the technology works although NIC teaming is a brand new feature to Windows Server 2012 the technology itself is not brand new and has actually existed for a number of years Windows Server 2012 is the first version of Windows to come with NIC teaming actually built into the operating system if you wanted to use NIC teaming prior to Windows Server 2012 you would have no choice but to use a third-party product the NIC teaming feature included with Windows Server 2012 and Windows Server 2012 r2 allows NIC teaming to be configured from the software layer this provides a number of advantages first it means that the administrator is not required to purchase any special network adapters to get the feature to work with NIC teaming you can create a team using network adapters from practically any hardware vendor it is worth noting at this point that it is recommended that you use network adapters from the same vendor if possible but this is not essential also the administrator is not required to make any complex configurations on the network adapters themselves everything you need to configure your adapters for NIC teaming is included with Windows Server 2012 so how exactly does Windows create the NIC team to understand this let's look at an example imagine that you have a server running either Windows Server 2012 or Windows Server 2012 r2 this server has a number of network cards installed in order to combine the adapters into a team Windows will use what is called a teaming solution the job of the teaming solution is to create a single virtual network adapter out of the for physical network adapters the virtual network adapter is then presented to the operating system in other words the operating system is fooled by the teaming solution into thinking that there is just one network adapter installed in the server just like with a physical network adapter the administrator is then able to assign the virtual network adapter an IP address any traffic sent to and from this IP address will then be distributed across all of the physical adapters in the team of course this is largely dependent on how you set up and configure your NIC team before you implement NIC teaming on your servers the first decision you have to make is which teaming mode you want to use there are two main types of teaming modes available these are switch independent teaming or switch dependent teaming the main difference between the two teaming modes is that switch independent teaming requires no additional Hardware supports from the switch is on your network switch dependent teaming however is as the name suggests dependent on your network switches being configured correctly let's start by taking a closer look at switch independent teaming switch independent teaming is the easiest and arguably the most common form of NIC teaming available what makes switch independent teaming so appealing is that all of the configuration for the NIC team is done on the server itself absolutely no configuration of the network switches is required to get switch independent teaming to work with switch independent teaming the switches on your network are completely unaware that the NIC team even exists another reason why administrators may opt for switch independent teaming is that you are able to connect the adapters in your NIC team to different switches for instance if you have a server with three network adapters configured in a team as long as switch independent teaming is used you are able to connect the adapters to three different switches this provides you with an additional layer of redundancy because if one of the switches were to fail the server is still able to communicate with the rest of the network using the other switches understand switch independent teaming does not require the use of multiple switches it merely makes it possible there is nothing stopping you from connecting all three adapters to the same switch if you really wanted to the disadvantage of switch independent teaming is that all inbound and outbound traffic for the NIC team is managed entirely by windows generally speaking windows is better at managing outbound traffic than incoming traffic however Windows is not always capable of making the most intelligent decisions for balancing traffic evenly as a result some of your adapters could be more heavily utilized than others this is why some network administrator's prefer to use other configurations such as switched dependent teaming there are two types of switch dependent teaming the first is static teaming and the second is LACP or link aggregation control protocol both static teaming and LACP require hardware support from the network switch in order to work that is the administrator is quite literally required to log on to the switch and configure it accordingly this makes static teaming and LACP harder to implement static teaming uses the protocol 802.3 ad to nominate specific ports on the switch that can be used for NIC teaming LACP does the same except it uses the protocol 802 dots one a X unsurprisingly this means two things first static teaming and LACP allow you to use just one network switch that is all of your adapters must be plugged into the same switch it is not possible to achieve redundancy at the switch level if you opt for switch dependent teaming also since the ports on the switch themselves are statically configured the network adapters that make up the NIC team must be plugged into the correct ports unlike switch independent teaming when switch dependent teaming is used the switch is fully aware of the NIC teams exist the main advantage of switch dependent teaming is that the switch is able to assist the knick team by load-balancing incoming traffic among all of the adapters in the team that is incoming traffic should in theory be distributed evenly amongst all the adapters load balancing of incoming traffic is something that windows struggles to achieve by itself with switch independent teaming of course all of this is dependent on your networks which supporting static teaming and/or LACP some switches do not support it at all others may support just one of these modes and others will support both since it is not possible for me to demonstrate how to configure static teaming and LACP on every single model of switch later in the video when I demonstrate NIC teaming to you I will stick to switch independent teaming now that we are familiar with the available teaming modes the next topic to discuss is load balancing modes load balancing modes determine how network traffic is load balanced that is how it is divided up among the network adapters in the NIC team before we go through the different load balancing modes it is important to understand that with any load balancing mode Microsoft has attempted to keep all data packets associated with the same TCP stream on the same network adapter but what exactly do I mean by this well let's consider an example let's say that you have a server running either Windows Server 2012 or Windows Server 2012 r2 this server is a very busy file server hosting thousands of shared folders when a client computer requests a file from file server before the file is transferred to the client it is first broken down into smaller segments these segments are called packets since these packets make up the same file they are considered to be part of the same TCP stream during transportation the problem is if these packets are sent out over different network adapters there is no way of telling what order the packets will arrive in when they get to their destination that is it is possible for packets to arrive out of order when this happens the out of order packets will have to be reordered once they arrive at the client this of course requires more processor power and RAM memory from the client to stop this from happening all of the load balancing modes in NIC teaming will attempt to send all packets that belong to the same TCP stream over the same network adapter increasing the chances that they arrive in order let's now take a look at the different load balancing algorithms the first load balancing mode is called address hash with address hash all of the outbound network traffic that is traffic that is sent out from the server is load balanced based on properties taken from the destination computer such as the destination computers MAC address IP address or even port numbers to demonstrate this better let's go back to our file server from earlier let's say that a client computer named client 1 requires access to a file hosted on the file server client 1 has a mac address of 0 0 1 5 5 d 0 1 0 1 0 0 and an IP address of one ninety two dot one sixty eight dot one dot one hundred when client one requests the file from the file server windows will use clients ones MAC address and IP address to create what is called a hash or a number all of the packets that make up the file are then marked with this hash value for demonstration purposes I have illustrated this as hash one two three four all data packets that have the hash value of hash one two three four are considered to have the same destination consequently these packets will be sent out using the same network adapter in the team when a new client computer named client 2 comes along the MAC address and IP address of this computer will be different as such when client 2 requests a file windows will generate a completely different hash value and will send this traffic via a different network adapter in the team as more clients come along these will also be assigned their own hash values and will be allocated and adapter in short address hash ensures that all TCP streams for a particular computer always use the same network adapter but we'll split the streams up as much as possible over different adapters as you can see address hash is very good at dividing up TCP streams however it does not always guaranteed the best load balancing solution for instance if clients 2 and clients four have a habit of requesting much larger files more frequently than client 1 and client 3 it stands to reason that the adapter assigned to clients 2 and 4 will be more heavily utilized let's now take a look at bound traffic with address hash all traffic that is sent to the server will arrive via the same network adapter it does not matter whether you have just two adapters or thirty-two adapters in the NIC team traffic will always be delivered to the server via just one of these adapters this essentially means that with this algorithm the server can only accept as much traffic as the bandwidth on one of the adapters allow the next load balancing mode is hyper-v port as the name suggests hyper-v port was designed for servers hosting hyper-v virtual machines with hyper-v ports every virtual machine that uses the NIC team will send and receive all of its traffic via the same network adapter this is achieved using the MAC address of the virtual machine for instance imagine that you have a server that has the hyper-v role installed this server has three virtual machines each with their own MAC address the server also has three network adapters that have been combined together into a NIC team on the server you create a virtual switch from the teemed adapter and attach all three virtual machines to it what essentially happens here is each virtual machine is allocated a network adapter from the team to send and receive its traffic since there are three adapters in this particular NIC team every virtual machine gets its own adapter if a fourth virtual machine is later added this virtual machine will like the others be assigned and adapter to route its traffic when this is the case two virtual machines will have no choice but to share the same adapter although hyper-v port is very good at load balancing traffic at the virtual machine level perfect load balancing is still not guaranteed for instance it is possible that the two virtual machines that share the same adapter could be very bandwidth intensive machines meanwhile the other two virtuals that have their own adapters may not utilize the bandwidth so much as such hyper-v port is best used when you are running virtual machines that have similar bandwidth requirements one argument for hyper-v ports though is that it does to some degree provide load balancing for incoming traffic since each virtual machine also receives its traffic from its allocated network adapter the only limitation to hyper-v port is that it is designed specifically for virtual machines the final load balancing mode to discuss is dynamic the dynamic load balancing algorithm is only available if you are using Windows Server 2012 r2 dynamic load balancing was added as an improvement to NIC teaming by combining certain aspects of address hash and hyper-v ports into one mode let's start by looking at outbound traffic dynamic load balancing handles outbound traffic in the same way as address hash that is outbound traffic is load balanced across the adapters based on a hash value that is calculated from either the MAC address IP address or port numbers of the destination computer what makes dynamic particularly appealing is that unlike with address hash it is able to redirect TCP streams to different adapters that is if one network adapter is particularly overwhelmed dynamic is able to shift some of the TCP streams onto a different adapter to visualize this better let's take the example of a busy email server this server has two network adapters that are combined into a NIC team at present there are two TCP streams one on each adapter sending data packets over the network however you can clearly see that the TCP stream on the first adapter is very large and the TCP stream on the second adapter is not so large if a third TCP stream were to commence dynamic load balancing is intelligent enough to have this TCP stream use the second adapter since this is not being utilized as much likewise if the TCP streams on the first adapter were to subside to the point where it is now being underutilized dynamic load balancing will address this by shifting some of the TCP streams from the second adapter over to the first dynamic load-balancing is able to detect when a network adapter is underused by looking for what are called flow loads in TCP streams a flow load is a brief but natural pause in network traffic that is during a TCP stream packets will be sent followed by a brief pause then more packets will be sent followed by another brief pause and then followed by more packets every TCP stream has flow loads that occur naturally flow loads are completely normal and are by design by measuring the amount of flow Lots on a network card dynamic load-balancing is able to make an educated guess on when it best to shift TCP streams to different adapters with regards to incoming traffic dynamic load-balancing handles incoming traffic in the same way as hyper-v port meaning that dynamic is fully optimized for use in a hyper-v environment now that we have covered the different methods of configuring nic teaming let's now take a look at how to set it up I will now change over to my Windows Server 2012 r2 server so that I can demonstrates how to set up and configure NIC teaming this is a clean installation of Windows Server 2012 r2 straight out of the box the only configuration I have made is changing the hostname of the server to server 1 to begin with I will open server manager and will select local server from the top left corner in the properties section at the top notice that there is an option for NIC teaming and that the feature is disabled by default beneath this you can see all of the individual network adapters that are installed in this server in my case I have 3 network adapters installed named Ethernet Ethernet 2 and Ethernet 3 since this is a clean installation of Windows Server 2012 r2 all of the adapters are set to receive ipv4 addresses via DHCP which is the default configuration ipv6 is also enabled let's now take a closer look at the 3 network adapters by opening network connections as you can see my 3 network adapters Ethernet Ethernet 2 and Ethernet 3 have all appeared listed to view the configuration of a network adapter simply right-click on it and select properties which I will do now for my Ethernet adapter from the list of items notice that I am able to configure either an ipv4 or an ipv6 address however notice that there is one item which is on ticked called the Microsoft network adapter multiplexer protocol this is essentially the protocol that Microsoft uses to provide load balancing and failover capability for network adapters this is also the protocol that is used to combine the adapters into a NIC team since NIC teaming is disabled by default it makes sense that this protocol would also be disabled to prove that this is the case for all of my adapters I will close the properties of my Ethernet adapter and will open the properties for my Ethernet to adapter and for my Ethernet 3 adapter you can clearly see that the Microsoft network adapter multiplexer protocol is disabled for all of the adapters I will now close out of network connections and will return to server manager to enable NIC teaming for Windows Server 2012 and Windows Server 2012 r2 click on the disabled link next to the option in server manager this opens the nic teaming dialog box to create a nic team you first have to select which server you want to create the team on this can be done from the servers section at the top since this is the only server I have added to my server manager console it is selected by default in the bottom right corner notice that we have a section named adapters and interfaces this section shows you which adapters in the server are currently part of a NIC team and those which can be added to a Knick team if you wish since I do not yet have a Knick team all of my adapters are listed as available to be added to a team finally in the bottom left corner we have the section teams this is where the knick teams are listed that is once you have created a Knick team it will appear in this section since I do not currently have a Knick team nothing is listed to create your first NIC team in the team section click on the tasks button and select new team from the drop-down list this opens the new team dialog box to create a NIC team the first thing you must do is choose a team name to identify it for now I will enter a team name of server 1 NIC team 1 after choosing a name the next task is to decide which adapters will be made members of the NIC team as you can see my three network adapters Ethernet Ethernet 2 and Ethernet 3 are all listed as possible candidates to add an adapter to the team simply tick the check box to the left of the adapter for now I will add my Ethernet and Ethernet to network adapters to the team after choosing your adapters click the additional properties link from here you are able to configure the advanced features of NIC teaming the first option allows you to choose a teaming mode by default this is set to switch independent which if you recall allows you to connect your adapters to different switches however you can modify this to use one of the switch dependent modes of static teaming or LACP instead of course both of these will involve some configuration of the network switch itself for now I will leave this on switch independent next you can choose the load balancing mode on Windows Server 2012 servers you can choose between address hash or hyper-v port on Windows Server 2012 r2 servers you also get an additional option of dynamic choosing a load balancing mode is simply a matter of selecting it from the drop down list the last option standby adapter determines whether or not you want one of your nominated network adapters to function as a standby adapter if you recall from earlier the job of a standby adapter is to sit and wait for an active network adapter to fail when an active network adapter fails the standby adapter will step in and take its place by default windows will attempt to make all of your network adapters active to increase the throughput of the server however if you would rather use NIC teaming with a standby adapter you are able to choose one of your nominated adapters from the drop-down list to function as a standby adapter personally I am a fan of keeping all adapters in the NIC team active for maximum performance so I will leave this on none all adapters active and will then click the ok button after a short wait windows will create the NIC team it is worth noting at this point that rather curiously when the NIC team is first created you may find that one or more of your adapters will report a status of faulted connection pending and your NIC team will appear to have prob if this happens do not panic I have created a lot of Knick teams and have found that it can take up to 30 seconds before the team is properly established and the adapters reports the correct status once the NIC team has been created you will immediately notice a few changes to the NIC teaming screen first notice that in the team section our server 1 NIC team one team has now appeared and is reporting a status of ok also in the adapters and interfaces section notice that's my Ethernet and Ethernet two network adapters are listed under a new heading of server 1 NIC team 1 indicating that they are now part of a NIC team furthermore both adapters are reporting a state of active whereas my Ethernet 3 adapter is still listed as available to be added to a team I will now close the NIC teaming dialog box and will return to server manager from here you will notice a few more changes firstly we can see that NIC teaming is now enabled on this server also nodes that's my Ethernet and Ethernet 2 adapters have disappeared and have been replaced with my server 1 NIC team 1 connection since Ethernet 3 is not part of the team it is still listed separately let's now take a closer look at the network cards by opening network connections the first thing that should be evident on this screen is that our server 1 NIC team 1 connection has appeared listed before I look at this though I would first like to take a closer look at my Ethernet and Ethernet 2 adapters so I will right click on my Ethernet adapter and will select properties since my Ethernet adapter is now part of a NIC team you will notice that all of the items from earlier are now unticked also note that I have lost the ability to configure an ipv4 and an ipv6 address on this adapter in fact the only item that is now ticked is the Microsoft network adapter multiplexer protocol I mentioned earlier if you recall this is the protocol that allows the adapter to be used for load balancing and failover in NIC teaming since the adapter is now part of a NIC team it makes sense that this will be enabled this is also the case for my ethernet 2 adapter so I will now close the properties screen and we'll return to network connections let's now take a closer look at my server 1 NIC team 1 adapter first I will right-click on the adapter and will select status notice that the speed of this adapter is 2 gigabits per second this is the combined bandwidth from my Ethernet and Ethernet 2 adapters I will now close the status screen and will open the properties for the adapter notice on this adapter I am able to configure an ipv4 or ipv6 address since it is a good practice to configure servers with static IP addresses I will enter a static ipv4 address on this adapter once complete I will close out of the properties and network connection screens and will return to server manager notice now that server manager has picked up the static ipv4 address I just entered now that the NIC team is enabled and configured I will now go back into the NIC teaming console so that I can simulate a network card failure as you can see in the adapters and interfaces section both my Ethernet and Ethernet two adapters are currently active to prove that I have network connectivity I will now open a command prompt from the start button from here I will ping another computer on my local area network as you can see I have successfully pinged the computer and have received four replies I will now simulate a network card failure by unplugging my Ethernet network adapter as you can see the status of my Ethernet network adapter has changed to faulted media disconnected yet the status of my Ethernet to adapter is still active assuming that NIC teaming has been properly configured this server despite the network card failure should still be able to communicate with the rest of the network so let's find out back on my command prompt window I will once again ping the same computer from earlier as you can see I am still getting replies indicating that network connectivity is still present so I will now close the command prompt and will plug my Ethernet adapter back in after a short wait the status of my Ethernet adapter will change back to active the next demonstration I would like to perform is how to add network adapters to an existing NIC team this is relatively easy to do first I will right click on my server 1 NIC team 1 team and will select properties this will open the team properties dialog box in my case I will add my Ethernet 3 network adapter to the team to make this adapter part of the team I will simply tick the check box to the left of the adapter and will then click the apply button after a short wait the adapter will be added to the team by default Windows will add the adapter as an active adapter however just for demonstration purposes I will make my Ethernet 3 adapter a standby network adapter instead to do this I will open the additional property section and for the standby adapter setting I will nominate Ethernet 3 as my standby adapter this essentially means that Ethernet 3 will no longer contribute any bandwidth to the NIC team unless either the Ethernet or Ethernet 2 network adapters fail to change the adapter to a standby adapter I will just click OK back on the nic teaming screen in the adapters and interfaces section notice that my ethernet 3 adapter is now listed under the server 1 nic team one team and is reporting a status of standby to show you how the standby adapter works I will once again unplug my ethernet network adapter as you can see my Ethernet network adapter is once again reporting a status of faulted media disconnected to compensate for the loss of bandwidth my Ethernet 3 adapter has stepped in and has changed from standby to active notice what happens when I plug my Ethernet adapter back in after a short wait the Ethernet adapter will change back to active and the ethernet 3 adapter will return to standby the final thing I would like to show you is how to delete a NIC team to delete a NIC team all you have to do in the team section is right-click on the team and select delete from the drop-down list at this point you will receive a prompt asking you to confirm the deletion of the knick team to delete the team click the delete team button after a short wait the team will be removed from the team section and the adaptors will return to their original state of available to be added to a team if I close the nic teaming dialog box and return to server manager you will notice that nic teaming is once again disabled furthermore my Ethernet Ethernet 2 and Ethernet 3 adapters are once again listed as individual adapters which can be configured separately to prove that this is definitely the case I will open network connections as you can see the server 1 nic team 1 connection has now disappeared and i am once again able to configure my individual adapters separately this concludes this tech tip from will I hope you have enjoyed this tech tip from us for more tech tips please feel free to browse our collection of videos on YouTube and don't forget to show your support by liking our videos leaving your comments and by subscribing to our channel many thanks and we'll see you on the next tech tip

Channel: techtipsfromwill

Views: 42,305

Rating: 4.8867927 out of 5

Keywords: Network Interface Controller (Computer Peripheral Class), NIC Teaming, Microsoft Windows (Operating System), Windows Server 2012 (Operating System), NIC, Load Balancing, Failover, Switch Independent, Switch Dependent, techtipsfromwill, address hash, hyper-v port

Id: pGSq_pq95e4

Length: 50min 27sec (3027 seconds)

Published: Fri Apr 03 2015