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1 Ethernet Switch and Ethernet Routing Switch Engineering > Technical Configuration Guide for Microsoft Network Load Balancing Enterprise Solutions Engineering Document Date: March 9, 2006 Document Version: 1.0

2 Copyright 2006 Nortel. All rights reserved. NORTEL CONFIDENTIAL: The information contained in this document is the property of Nortel. Except as specifically authorized in writing by Nortel, the holder of this document shall not copy or otherwise reproduce, or modify, in whole or in part, this document or the information contained herein. The holder of this document shall keep the information contained herein confidential and protect same from disclosure and dissemination to third parties and use same solely for the training of authorized individuals. This information is subject to change without notice. Nortel, the Nortel logo, Shasta, and Passport are trademarks of Nortel. SUN, SUNLINK, and SOLARIS are trademarks of Sun Microsystems Inc. SPARC is a trademark of SPARC International Inc. UNIX is a trademark licensed exclusively through X/Open Company Ltd. OPENVIEW is a trademark of Hewlett-Packard Company. ORACLE is a trademark of Oracle Corporation. Disclaimer This engineering document contains the best information available at the time of publication in terms of supporting the application and engineering of Nortel products in the customer environment. They are solely for the use by Nortel customers and meant as a guide for network engineers and planners from a network engineering perspective. All information is subject to interpretation based on internal Nortel test methodologies which were used to derive the various capacity and equipment performance criteria and should be reviewed with Nortel engineering primes prior to implementation in a live environment. NORTEL External Distribution 1

3 Abstract The document provides an overview on how to configure Nortel Ethernet & Ethernet Routing Switches to support Microsoft s Network Load Balancing (NLB) server clustering technology. NORTEL External Distribution 2

4 Table of Contents 1. OVERVIEW: NETWORK LOAD BALANCING UNICAST MODE OF OPERATION MULTICAST MODE OF OPERATION MAC ADDRESS FORMATS IMPLEMENTATION MODELS NETWORK LOAD BALANCING SWITCH SUPPORT NORTEL SWITCH SUPPORT MATRIX MULTICAST FLOOD SUPPRESSION DEPLOYING MICROSOFT NETWORK LOAD BALANCING CONFIGURATION WINDOWS 2003 SERVERS ETHERNET SWITCH SOFTWARE DEPENDENCIES CREATING A WINDOWS SERVER UNICAST CLUSTER CREATING A WINDOWS SERVER MULTICAST CLUSTER ETHERNET SWITCH CONFIGURATION EXAMPLE ERS 1600 CONFIGURATION EXAMPLE ERS 5500 CONFIGURATION EXAMPLE ERS 8300 CONFIGURATION EXAMPLE ERS 8600 CONFIGURATION EXAMPLE ERS 8600 CONFIGURATION EXAMPLE APPENDIX A. NLB PORT RULES OPTIONS B. RESOURCES & REFERENCE DOCUMENTS NORTEL External Distribution 3

5 1. Overview: Network Load Balancing Network Load Balancing is a clustering technology offered by Microsoft as part of all Windows 2000 / Windows 2003 Server family of operating systems. Network Load Balancing uses a distributed algorithm to load balance network traffic across a number of hosts, enhancing the scalability and availability of mission critical, IP based services, such as Web, VPN, Streaming Media, Firewalls, etc. Network Load Balancing also provides high availability by detecting host failures and automatically redistributing traffic to remaining operational hosts. Figure 1.1 Network Load Balancing Cluster With Network Load Balancing, each host runs separate copies of the desired server applications, such as Web Server, FTP Server, or ISA Firewall. Network Load Balancing distributes incoming client requests to the hosts in the cluster group. The load weight to be handled by each host can be configured by the administrator and hosts can be dynamically added or removed from the cluster as necessary. In addition, Network Load Balancing can direct all traffic to a designated single host, called the default host. Microsoft Network Load Balancing provides the following benefits: High availability for applications by redirecting incoming network traffic to working cluster hosts. If a cluster host fails or is offline, existing connections to an offline host are lost, but the Application remains available. In most cases (for example, with Web servers), client software automatically retries the failed connections, and the client may experience few second delay in receiving a response. Scalability by clustering of two or more host computers together. Clients access the cluster using either a single IP address for multiple applications or individual addresses for each application. The clients are unable to distinguish the cluster from a single server and applications do not identify that they are running in a cluster. Higher performance by distributing the incoming network traffic among one or more hosts assigned to the Network Load Balancing cluster. The hosts in the cluster then NORTEL External Distribution 4

6 concurrently respond to different client requests, even multiple requests from the same client. For example, a Web browser might obtain each of the multiple images in a single Web page from different hosts within a Network Load Balancing cluster. This speeds up processing and shortens the response time to clients. Figure 1.2 Example Cluster NORTEL External Distribution 5

7 1.1 Unicast Mode of Operation Microsoft s Network Load Balancing default setting is unicast mode. In unicast mode, Network Load Balancing replaces the network adapters MAC address with a cluster MAC address. All Network Load Balancing host adapters in a cluster share a common cluster MAC address and all frames forwarded to the cluster MAC address are received by all hosts in the cluster. Figure Unicast Mode MAC Address Assignment Sharing a common MAC address amongst multiple hosts works fine in shared media such as repeaters (hubs) but can cause issues in switched environments. An Ethernet switch forwards frames to hosts based on MAC addresses. An Ethernet switch does this by learning the MAC address of the host connected to each of its ports. The switch builds a forwarding database which provides a logical mapping of a MAC address to the port which it was learned on. A switch expects that a MAC address is unique, only connected to one port, and therefore will not associate a MAC address with multiple ports of the switch. As described above, Microsoft Network Load Balancing creates a cluster MAC address that is common to all hosts in a cluster. An Ethernet switch would learn this MAC address on multiple ports. Since the switch only associates a MAC address to a single port and not many ports, Network Load Balancing will not function correctly. Microsoft Network Load Balancing solves this problem by masking the cluster MAC address. When enabled, Network Load Balancing creates a bogus MAC address on each host adapter which starts with 02 and contains the host ID in the second octet. The bogus MAC address will appear in the Ethernet frame header and will be learned by the Ethernet switch rather than the cluster MAC address. This ensures that the Ethernet switch will not learn the cluster MAC addresses on multiple ports and will learn unique MAC addresses for each host in the cluster. Figure Unicast Mode MAC Address Masking NORTEL External Distribution 6

8 If each network adapters MAC address is unique, how are frames delivered to all members of the cluster? Microsoft Network Load Balancing solves this problem with IP. A client will learn the cluster MAC address associated with the virtual IP address using Address Resolution Protocol (ARP). When a client sends an ARP request for the MAC address of the clusters virtual IP address, the ARP response will contain cluster MAC virtual address and not the bogus MAC addresses. Frames from the client will then be forwarded to the clusters virtual IP address with a destination MAC address set to the cluster MAC address. On receipt of the frames, the Ethernet switch will perform a lookup and will not have a forwarding entry for the cluster MAC address. The switch will then flood the frames to all active ports in the broadcast domain so that all hosts in the cluster will receive the frames. Figure Traffic from Clients to a Cluster Flooding typically isn t a problem for incoming traffic because the majority of traffic is outbound, not inbound. However if there is a significant amount of inbound traffic and other servers are connected to the same switch, switch flooding can present a problem if the traffic is high enough. NORTEL External Distribution 7

9 1.2 Multicast Mode of Operation Multicast mode is the second option available for Network Load Balancing. In multicast mode, a multicast MAC address is assigned to all hosts in the cluster but the network adapter's built-in address is retained so that both addresses are used. The multicast MAC address is used for client-to-cluster traffic and the adapter MAC address is used for network traffic specific to the host computer. Microsoft Network Load Balancing multicast mode can be implemented with or without flood suppression. The default mode of operation does not support multicast flood suppression and uses a virtual cluster MAC address that starts with 03-bf. The second mode of operation supports multicast flood suppression by implementing IGMP and the clusters virtual MAC address starts with Figure Multicast Mode MAC Address Assignment Using multicast MAC addresses allows multiple computers to listen on the same MAC address. All the machines listening on the same multicast MAC address are referred to as a "multicast group". Frames sent to the multicast MAC address are accepted by all the network adapters listening to the multicast address and frames directed to a unicast MAC address are accepted by the single host that owns the particular unicast address. As previously mentioned, Network Load Balancing requires that all members of the cluster receive the frames from the clients. By default Layer 2 switches will flood multicast frames to all active switch ports in the broadcast domain which ensures that all hosts in the cluster will receive the frames. Frames from clients are forwarded to the clusters virtual IP address with a destination MAC address set to the cluster multicast MAC address. A client will learn the multicast MAC address of the clusters virtual IP address using Address Resolution Protocol (ARP). When a client sends an ARP request for the MAC address of the clusters virtual IP address, the ARP response will contain the clusters multicast MAC address. Frames from the client will then be forwarded to the clusters virtual IP address with a destination MAC address set to the cluster multicast MAC address. On receipt of the frames, the Ethernet switch will flood the frames to all active ports in the broadcast domain so that all hosts in the cluster will receive the frames. NORTEL External Distribution 8

10 Figure Traffic from Clients to a Cluster In multicast mode there can be problems with certain Routers and Routing Switches: 1. Some Routers or Routing Switches may not support the ability to map a unicast IP address with a multicast MAC address. 2. Some Routers or Routing Switches may not be able to dynamically learn the clusters virtual MAC address. 3. Some Ethernet Routing Switches only support the ability to associate an ARP entry to a single port. If Network Load Balancing hosts are directly connected to the Ethernet Routing Switch, the frames will not be flooded to all hosts in the cluster. This can be easily solved by moving the Network Load Balancing cluster hosts to a subtended Layer 2 Ethernet Switch so that the static ARP entry is associated to a single port. One advantage to implementing the multicast version of Network Load Balancing is the ability to leverage IGMP snooping and pruning which provides the ability to suppress multicast flooding on Ethernet switches and only flood frames to specific hosts that request membership to the multicast group. NORTEL External Distribution 9

11 1.3 MAC Address Formats Microsoft Network Load Balancing can implement either Unicast or Multicast MAC addresses depending on how Network Load Balancing is deployed. The following section describes the IEEE formatting of MAC addresses used with Ethernet as well as the MAC address formats used with Microsoft Network Load Balancing for unicast and multicast modes. In Ethernet there are four types of MAC addresses defined by IEEE: MAC Address Type Globally Unique Locally Administered Multicast Broadcast MAC Address Range x0-xx-xx-xx-xx-xx x4-xx-xx-xx-xx-xx x8-xx-xx-xx-xx-xx xc-xx-xx-xx-xx-xx x2-xx-xx-xx-xx-xx x6-xx-xx-xx-xx-xx xa-xx-xx-xx-xx-xx xe-xx-xx-xx-xx-xx x1-xx-xx-xx-xx-xx x3-xx-xx-xx-xx-xx x5-xx-xx-xx-xx-xx x7-xx-xx-xx-xx-xx x9-xx-xx-xx-xx-xx xb-xx-xx-xx-xx-xx xd-xx-xx-xx-xx-xx xf-xx-xx-xx-xx-xx (exception broadcast address) FF-FF-FF-FF-FF-FF Globally Unique Globally unique addresses are allocated by the IEEE in blocks containing 2^24 (16,777,216) addresses and start with even numbers. In each allocation, the first 3 octets are fixed (e.g is Nortel) and the last three octets are variable (e.g through FF-FF-FF). The fixed portion of the allocation is known formally as the Organizationally Unique Identifier (OUI) and is used informally as the Vendor ID Locally Administered Locally administered addresses are MAC addresses which have the second least significant bit of the first octet is set to '1' (for example, 'xxxxxx1x'). Locally administered addresses enable administrators to assign MAC addresses using their own scheme Multicast Multicast addresses have the least significant bit of the first octet set to '1' and start with an odd number. Ethernet multicast addressing is used by protocols which require efficient communication among groups of hosts. NORTEL External Distribution 10

12 1.3.4 Broadcast Broadcast address is a special case where all bits of the MAC address are set to '1' (e.g. FF-FF- FF-FF-FF-FF). When an adapter receives a packet with a destination broadcast address, it always passes it to the operating system for further processing Network Load Balancing Unicast Mode When Microsoft Network Load Balancing is deployed in unicast mode, the globally unique MAC address on the hosts network adapter is replaced with a locally administered MAC address assigned by Microsoft. The locally administered MAC address starts with a 02:xx prefix and the second octet will contain the host id of the host in the cluster. The clusters virtual MAC address is also a locally administered MAC address and starts with a 02:bf prefix. Figure Host Unicast MAC Assignment Network Load Balancing Multicast Mode When Microsoft Network Load Balancing is deployed in multicast mode, the globally unique MAC address on the hosts network adapter is retained. The clusters virtual MAC address is Multicast MAC address assigned by Microsoft and will start with a 03:bf prefix. All the hosts in cluster will be configured with the same multicast cluster MAC address. Figure Host Multicast MAC Assignment NORTEL External Distribution 11

13 1.4 Implementation Models Microsoft s Network Load Balancing can be deployed using one of four models. This section provides a brief overview of the supported models and provides advantages and disadvantages of each Single Network Adapter in Unicast Mode The single network adapter unicast model is suitable for a cluster in which ordinary network communication among cluster hosts is not required and there is limited dedicated traffic from outside the cluster subnet to specific cluster hosts. Figure Single Adapter Unicast Mode Advantages One network adapter per host is required. Minimum configuration is required as unicast mode is the default. Works with all routers and L2 switches. Disadvantages Network communication between cluster hosts is not possible. All traffic from clients to cluster hosts will be flooded. Not supported by all L3 switches. NORTEL External Distribution 12

14 1.4.2 Single Network Adapter in Multicast Mode The single network adapter multicast model is suitable for a cluster in which ordinary network communication among cluster hosts is necessary or desirable, but in which there is limited dedicated traffic from outside the cluster subnet to specific cluster hosts. Figure Single Adapter Multicast Mode Advantages One network adapter per host is required. Network communication between cluster hosts is permitted. Supports Internet Group Management Protocol (IGMP) on the cluster hosts to control flooding on the switch. Disadvantages Some Routers or Routing Switches may not support the ability to map a unicast IP address with a multicast MAC address. Some Routers or Routing Switches may not be able to dynamically learn the clusters virtual MAC address. By default Windows 2003 Server implements IGMPv3 which is not supported by some L2 switches. A registry modification is required to change the default IGMPv3 setting to IGMPv1 or IGMPv2 (See Appendix B). NORTEL External Distribution 13

15 1.4.3 Multiple Network Adapters in Unicast Mode The multiple network adapter unicast model is suitable for a cluster in which ordinary network communication among cluster hosts is necessary or desirable. It is also appropriate when you want to separate the traffic used to manage the cluster from the traffic occurring between the cluster and client computers. Figure Multiple Adapters Unicast Mode Advantages Network communication between cluster hosts is permitted. This model works with all routers and L2 switches. Disadvantages This model requires a second network adapter. All traffic from clients to cluster hosts will be flooded. Not supported by all L3 switches. NORTEL External Distribution 14

16 1.4.4 Multiple Network Adapters in Multicast Mode The multiple network adapter multicast model is suitable for a cluster in which ordinary network communication among cluster hosts is necessary and in which there is heavy dedicated traffic from outside the cluster subnet to specific cluster hosts. Figure Multiple Adapters Multicast Mode Advantages Network communication between cluster hosts is permitted. Cluster performance may be enhanced. Disadvantages This model requires a second network adapter. Some Routers or Routing Switches may not support the ability to map a unicast IP address with a multicast MAC address. Some Routers or Routing Switches may not be able to dynamically learn the clusters virtual MAC address. By default Windows 2003 Server implements IGMPv3 which is not supported by some L2 switches. A registry modification is required to change the default IGMPv3 setting to IGMPv1 or IGMPv2 (See Appendix B). There is no restriction on the number of network adapters that can be bound to network load balancing on each computer: Different hosts can have a different number of adapters, but you can never have more than one adapter on a computer be part of the same cluster. Network Load Balancing does not support a mixed unicast/multicast environment within a single cluster. Within each cluster, all network adapters in that cluster must be either multicast or unicast; otherwise, the cluster will not function properly. NORTEL External Distribution 15

17 2. Network Load Balancing Switch Support Microsoft Network Load Balancing is supported in some fashion by all Nortel Ethernet Switches. However due to the nature of how the Microsoft Network Load Balancing feature works, Network Load Balancing support is dependent on where the clustered servers are placed in the network as well as how the Ethernet Switch the clustered servers are connected to is configured. 2.1 Nortel Switch Support Matrix Ethernet Switch Model Unicast Support (L2 Switching) Unicast Support (L3 Routing) Multicast Support (L2 Switching) Multicast Support (L3 Routing) Ethernet Switch 325 Yes N/A Yes (Note 1) N/A Ethernet Switch 425 Yes N/A Yes (Note 1) N/A Ethernet Switch 470 Yes N/A Yes (Note 1) N/A Ethernet Switch T-PWR Yes N/A Yes (Note 1) N/A Ethernet Routing Switch 1600 Yes No (Note 2) Yes (Note 1) No (Note 3) Ethernet Routing Switch 5500 Yes No (Note 2) Yes (Note 1) No (Note 3) Ethernet Routing Switch 8300 Yes No (Note 2) Yes (Note 1) No Ethernet Routing Switch 8600 Yes Yes Yes (Note 1) Yes (Note 4) Table Supported Switches Note 1 By default Windows 2003 Servers implement IGMPv3 which is not currently supported on Nortel switches. If multicast flood suppression is desired the Windows 2003 servers registry can be modified to support IGMPv1 or IGMPv2 (See Appendix B). Note 2 The Ethernet Routing Switch models 1600, 5500 and 8300 can provide unicast support in certain routing scenarios as long as the Network Load Balancing cluster of servers are connected to a subtended to a Layer 2 switch. Note 3 The Ethernet Routing Switch models 1600 and 5500 can provide multicast support in certain routing scenarios as long as the Network Load Balancing cluster of servers are connected to a subtended to a Layer 2 switch. These models support the ability to create a static ARP entry where a Multicast MAC address is mapped to a Unicast IP address. Note 4 The Ethernet Routing Switch 8600 does not provide support for multicast mode with IGMP flood suppression when the Network Load Balancing cluster of servers and clients are directly connected to the switch and the switch is performing IP routing. NORTEL External Distribution 16

18 2.2 Multicast Flood Suppression In certain deployments where client traffic to the cluster hosts is high, it may be desirable to implement flood suppression so that other devices in the IP subnet are not unnecessarily receiving cluster traffic. Microsoft Network Load Balancing in multicast mode supports the ability to suppress flooding using Internet Group Management Protocol (IGMP). When enabled, an Ethernet Switch can snoop on IGMP Queries, Reports & Leave messages and prune the multicast traffic so that only specific hosts that request membership to the multicast group will receive the traffic. When IGMP is enabled on the Windows 2003 Servers and the Ethernet Switch, traffic from clients is only flooded out of the ports that the Network Load Balancing cluster hosts are connected and is not flooded out of any other port which reduces the amount of unnecessary traffic that other hosts in the IP subnet receive. Ethernet Switch Model IGMPv1 IGMPv2 IGMPv3 Ethernet Switch 325 Yes Yes Future Ethernet Switch 425 Yes Yes Future Ethernet Switch 470 Yes Yes Future Ethernet Switch T-PWR Yes Yes Future Ethernet Routing Switch 1600 Yes Yes Future Ethernet Routing Switch 5500 Yes Yes Future Ethernet Routing Switch 8300 Yes Yes Future Ethernet Routing Switch 8600 Yes Yes Future Table Ethernet Switch Flood Suppression Support By default Windows 2003 Server implements IGMPv3 which is not supported by some L2 switches. A registry modification is required to change the default IGMPv3 setting to IGMPv1 or IGMPv2 (See Appendix B). NORTEL External Distribution 17

19 2.3 Deploying Microsoft Network Load Balancing The following section describes the tested and verified topologies that can be used with Nortel Ethernet Switches to deploy Windows 2003 clustered servers using the Microsoft Network Load Balancing feature Single Subnet Environments Single subnet environments are supported on all Nortel Ethernet & Ethernet Routing Switch models for unicast and multicast modes with no additional switch configuration being required. If Ethernet Routing Switch models 1600, 5500, 8300 or 8600 are utilized, the Ethernet Routing Switches must be configured for Layer 2 only and must not have IP routing enabled or the unicast and multicast frames will not be flooded to all the hosts in the cluster which will result in the clients not being able to communicate with the clusters IP address. Figure Ethernet Switch Example NORTEL External Distribution 18

20 2.3.2 Multiple Subnet Subtended Switch Deployments Multiple subnet environments are supported by all Nortel Ethernet Routing Switch models when the Network Load Balancing clusters of servers are connected to a subtended Layer 2 Ethernet Switch Ethernet Routing Switch 1600 The Ethernet Routing Switch 1600 may be used as a centralized Layer 3 device when Network Load Balanced servers and clients are connected to subtended Layer 2 switches. The Ethernet Routing Switch 1600 supports Network Load Balanced servers running unicast or multicast modes. If multicast mode is enabled with no IGMP flood suppression, the Ethernet Routing Switch 1600 requires that a static ARP entry be created so that the client can communicate with the clusters virtual IP address. If multicast mode is enabled with IGMP flood suppression, the Ethernet Routing Switch 1600 dynamically learns the ARP entry and no additional configuration is required. Figure Ethernet Routing Switch 1600 Example NORTEL External Distribution 19

21 Ethernet Routing Switch 5500 The Ethernet Routing Switch 5500 may be used as a centralized Layer 3 device when Network Load Balanced servers and clients are connected to subtended Layer 2 switches. The Ethernet Routing Switch 5500 supports Network Load Balanced servers running unicast or multicast modes. If multicast mode is enabled (with or without IGMP flood suppression) the Ethernet Routing Switch 5500 requires that a static ARP entry be created so that the client can communicate with the clusters virtual IP address. Figure Ethernet Routing Switch 5500 Example NORTEL External Distribution 20

22 Ethernet Routing Switch 8300 The Ethernet Routing Switch 8300 may be used as a centralized Layer 3 device when Network Load Balanced servers and clients are connected to subtended Layer 2 switches. The Ethernet Routing Switch 8300 supports Network Load Balanced servers in unicast mode only but can route the client traffic to the clusters virtual IP address. Figure Ethernet Routing Switch 8300 Example NORTEL External Distribution 21

23 Ethernet Routing Switch 8600 The Ethernet Routing Switch 8600 may be used as a centralized Layer 3 device when Network Load Balanced servers and clients are connected to subtended Layer 2 switches. The Ethernet Routing Switch 8600 supports Network Load Balanced servers running unicast or multicast modes. If multicast mode is enabled (with or without IGMP flood suppression), the Ethernet Routing Switch 8600 will dynamically learn the ARP entry so no additional configuration is required. Figure Ethernet Routing Switch 8600 Example NORTEL External Distribution 22

24 2.3.3 Multiple Subnet Single Switch Deployments The Ethernet Routing Switch 8600 may be used as a centralized Layer 3 device when Network Load Balanced servers and clients are directly connected to the switch. The Ethernet Routing Switch 8600 supports Network Load Balanced servers running unicast or multicast modes but does require that unicast or multicast flooding features be enabled so that the frames are flooded to all hosts in the cluster. If multicast mode is enabled, the Ethernet Routing Switch 8600 will dynamically learn the ARP entry so no additional configuration is required. The Ethernet Routing Switch 8600 however does not support multicast mode with IGMP flood suppression in this configuration. Figure Ethernet Routing Switch 8600 Example NORTEL External Distribution 23

25 3. Configuration 3.1 Windows 2003 Servers The Windows 2003 Servers used in the following examples were configured as follows: The Windows 2003 servers have been updated with Service Pack 1 with all the current updates applied. The Windows 2003 servers have two 10/100/1000BASE-T Ethernet Network Adaptors installed. The first Ethernet Network Adaptor was used for Server Management and the second Ethernet Network Adaptor was used for Network Load Balancing. Internet Information Services (IIS) is installed and operational with a default web site tied to the Clusters Virtual IP Address. 3.2 Ethernet Switch Software Dependencies The Ethernet Switches used in the following examples were based on the following software versions: Ethernet Routing Switch 8600 Release (Note 1) Ethernet Routing Switch 8300 Release Ethernet Routing Switch 5500 Release Ethernet Routing Switch 1600 Release Ethernet Routing Switch 460/470 Release Note 1 The Ethernet Routing Switch 8600 has several specific Network Load Balancing features that have been added to provide Network Load Balancing Support when the Ethernet Routing Switch 8600 is proving IP routing between subnets (VLANs): NLB multicast flooding Added in release NLB unicast flooding Added in release (not available in release 4.0.x) The information in this document was created from devices in a specific lab environment. If you are working in a live network environment, please ensure that you fully understand the impact of any command or configuration change before doing it. NORTEL External Distribution 24

26 3.3 Creating a Windows Server Unicast Cluster For this configuration example we will create a Network Load Balancing Cluster in unicast mode to provide high available HTTP web services. This example uses two Windows 2003 Advanced Servers with Internet Information Services (IIS) installed and operation with both IIS server providing identical web content. Both servers will have two Ethernet Network Adaptors installed where the first adaptor will be used for management and the second adaptor will be bound to the cluster to service client requests. Figure NLB Unicast Server Configuration Step 1 Start the Network Load Balancing Manager The Microsoft Network Load Balancing Manager simplifies the creation and management of Network Load Balancing Server Clusters. To start the Network Load Balancing Manager on a Windows 2003 server, select Start, Programs, Administrative Tools and click on Network Load Balancing Manager. You can optionally start the Network Load Balancing Manager by typing NLBmgr in the console or by selecting Start and clicking Run and typing in NLBmgr. NORTEL External Distribution 25

27 Network Load Balancing can optionally be configured on each individual server by modifying the Network Adaptors properties and binding the Network Load Balancing protocol to the Adaptor. This method is much more complex and does not provide visibility into the state of the cluster so for the purpose of this document the Network Load Balancing Manager will be used. Step 2 Creating a New Cluster In the Network Load Balancing Manager application, right click on Network Load Balancing Clusters and select New Cluster. A new cluster can also be created by selecting the Cluster menu and clicking on New. NORTEL External Distribution 26

28 Step 3 Modifying Cluster Parameters The Cluster Parameters window allows you to specify the Clusters Virtual IP Address, a full DNS name for the service and the Cluster operational mode. For this example we will use a Cluster Virtual IP Address of The Cluster Virtual IP Address is placed in the same IP subnet as the IP Addresses assigned to each of the second Ethernet Adaptors installed in each Server (see figure 3.1.1). We will enter in the full DNS name which is configured on our DNS server and set the Cluster operational mode to Unicast. Click Next NORTEL External Distribution 27

29 Step 4 Adding Additional Cluster IP Addresses The Cluster IP Address window allows you to bind additional Virtual IP Addresses to the Cluster. This can be useful in applications such as Web Servers where multiple sites are being hosted and each site requires a unique IP Address. For the purpose of this example we will be hosting a single Web site so no additional addresses are required. Click Next NORTEL External Distribution 28

30 Step 5 Port Rules The Port Rules window allows you to specify how the traffic is handled by the hosts in the cluster. Port rules allow you to define which protocols the hosts in the cluster support, how the traffic is distributed between the hosts as well as weigh each member in the cluster. The rules are very flexible and a single rule could be used to service a multiple applications or multiple rules can be used to limit applications to specific ports or hosts. For example a Web Server servicing HTTP & HTTPS requests could have a single rule with the port range set for Alternatively two rules could be created with the first rule port range set for and a second rule with the port range set for By default all TCP / UDP traffic from received on the cluster Virtual IP Address will be distributed to all hosts in the cluster. For our example we are hosting a Web Server so we will modify the default port rules so that only HTTP traffic is serviced by the hosts. To modify the default rule, click on Edit NORTEL External Distribution 29

31 Step 6 Modifying Port Rules In the Add/Edit Port Rule window, modify the From and To port values to 80 so that the cluster is only servicing HTTP traffic. For a complete description of all the available options in this window, please see Appendix A at the end of this document. Click OK Click Next NORTEL External Distribution 30

32 Step 7 Adding Labserver1 to the Cluster The Connect window allows us to add the first host that is to be a member of the cluster. In our example we have two Windows 2003 Advanced Servers named Labserver1 and Labserver2. In this step we will add Labserver1 and specify the Network Adaptor that will support the cluster. In the Connect window in the Host field, type in the name or IP Address of the first server that will be a member of the cluster. Click Connect and the Network Load Balancing Manager will attempt to contact the server. If successful, the Connection Status field should show Connected and a list of available Network Adaptors will be listed in the Interface name table. Select the Interface that is to participate in the cluster and click on Next. NORTEL External Distribution 31

33 Step 8 Modifying Labserver1 Host Parameters The Host Parameters window defines the Priority or Host ID for the cluster host instance, the unique IP Address bound to the Network Adaptor and the Initial host state. For our example server Labserver1 will be assigned as host 1. We will retain the IP Addressing that was initially assigned to the Network Adaptor and we will use the default state of Started. Click Finish NORTEL External Distribution 32

34 Once the Cluster Wizard completes, the newly configured cluster will be listed in the Network Load Balancing Manager window along with the host Labserver1. When the Network Load Balancing Manager has completed configuring the host, the host state should be listed as Converged. NORTEL External Distribution 33

35 Step 9 Adding Additional Hosts to the Cluster In the Network Load Balancing Manager application, right click on the cluster you just created (e.g. and select Add Host to Cluster. A new host can also be added to the cluster by selecting the Cluster menu and clicking on Add Host. NORTEL External Distribution 34

36 Step 10 Adding Labserver2 to the Cluster In the Connect window in the Host field, type in the name or IP Address of the second server that will be a member of the cluster. Click Connect and the Network Load Balancing Manager will attempt to contact the server. If successful, the Connection Status field should show Connected and a list of available Network Adaptors will be listed in the Interface name table. Select the Interface that is to participate in the cluster and click on Next. NORTEL External Distribution 35

37 Step 11 Modifying Labserver2 Host Parameters The Host Parameters window defines the Priority or Host ID for the cluster host instance, the unique IP Address bound to the Network Adaptor and the Initial host state. For our example server Labserver2 will be assigned as host 2. We will retain the IP Addressing that was initially assigned to the Network Adaptor and we will use the default state of Started. Click Finished NORTEL External Distribution 36

38 Once the second host has been successfully added to the cluster, the host state will change to Converged. NORTEL External Distribution 37

39 3.4 Creating a Windows Server Multicast Cluster For this configuration example we will create a Network Load Balancing Cluster in multicast mode to provide high available HTTP web services. This example uses two Windows 2003 Advanced Servers with Internet Information Services (IIS) installed and operation with both IIS server providing identical web content. Both servers will have two Ethernet Network Adaptors installed where the first adaptor will be used for management and the second adaptor will be bound to the cluster to service client requests. Figure NLB Multicast Server Configuration Step 1 Start the Network Load Balancing Manager The Microsoft Network Load Balancing Manager simplifies the creation and management of Network Load Balancing Server Clusters. To start the Network Load Balancing Manager on a Windows 2003 server, select Start, Programs, Administrative Tools and click on Network Load Balancing Manager. You can optionally start the Network Load Balancing Manager by typing NLBmgr in the console or by selecting Start and clicking Run and typing in NLBmgr. NORTEL External Distribution 38

40 Network Load Balancing can optionally be configured on each individual server by modifying the Network Adaptors properties and binding the Network Load Balancing protocol to the Adaptor. This method is much more complex and does not provide visibility into the state of the cluster so for the purpose of this document the Network Load Balancing Manager will be used. Step 2 Creating a New Cluster In the Network Load Balancing Manager application, right click on Network Load Balancing Clusters and select New Cluster. A new cluster can also be created by selecting the Cluster menu and clicking on New. NORTEL External Distribution 39

41 Step 3 Modifying Cluster Parameters The Cluster Parameters window allows you to specify the Clusters Virtual IP Address, a full DNS name for the service and the Cluster operational mode. For this example we will use a Cluster Virtual IP Address of The Cluster Virtual IP Address is placed in the same IP subnet as the IP Addresses assigned to each of the second Ethernet Adaptors installed in each Server (see figure 3.2.1). We will enter in the full DNS name which is configured on our DNS server and set the Cluster operational mode to Multicast. Click Next. You can optionally enable IGMP multicast support which can be used to provide Multicast flood suppression. If the IGMP multicast option is enabled, please ensure that the IGMP version on the Windows 2003 server is changed to support IGMPv2. Click Next. NORTEL External Distribution 40

42 Step 4 Adding Additional Cluster IP Addresses The Cluster IP Address window allows you to bind additional Virtual IP Addresses to the Cluster. This can be useful in applications such as Web Servers where multiple sites are being hosted and each site requires a unique IP Address. For the purpose of this example we will be hosting a single Web site so no additional addresses are required. Click Next NORTEL External Distribution 41

43 Step 5 Port Rules The Port Rules window allows you to specify how the traffic is handled by the hosts in the cluster. Port rules allow you to define which protocols the hosts in the cluster support, how the traffic is distributed between the hosts as well as weight each member in the cluster. The rules are very flexible and a single rule could be used to service a multiple applications or multiple rules can be used to limit applications to specific ports or hosts. For example a Web Server servicing HTTP & HTTPS requests could have a single rule with the port range set for Alternatively two rules could be created with the first rule port range set for and a second rule with the port range set for By default all TCP / UDP traffic from received on the cluster Virtual IP Address will be distributed to all hosts in the cluster. For our example we are hosting a Web Server so we will modify the default port rules so that only HTTP traffic is serviced by the hosts. To modify the default rule, click on Edit NORTEL External Distribution 42

44 Step 6 Modifying Port Rules In the Add/Edit Port Rule window, modify the From and To port values to 80 so that the cluster is only servicing HTTP traffic. For a complete description of all the available options in this window, please see Appendix A at the end of this document. Click OK Click Next NORTEL External Distribution 43

45 Step 7 Adding Labserver1 to the Cluster The Connect window allows us to add the first host that is to be a member of the cluster. In our example we have two Windows 2003 Advanced Servers named Labserver1 and Labserver2. In this step we will add Labserver1 and specify the Network Adaptor that will support the cluster. In the Connect window in the Host field, type in the name or IP Address of the first server that will be a member of the cluster. Click Connect and the Network Load Balancing Manager will attempt to contact the server. If successful, the Connection Status field should show Connected and a list of available Network Adaptors will be listed in the Interface name table. Select the Interface that is to participate in the cluster and click on Next. NORTEL External Distribution 44

46 Step 8 Modifying Labserver1 Host Parameters The Host Parameters window defines the Priority or Host ID for the cluster host instance, the unique IP Address bound to the Network Adaptor and the Initial host state. For our example server Labserver1 will be assigned as host 1. We will retain the IP Addressing that was initially assigned to the Network Adaptor and we will use the default state of Started. Click Finish NORTEL External Distribution 45

47 Once the Cluster Wizard completes, the newly configured cluster will be listed in the Network Load Balancing Manager window along with the host Labserver1. When the Network Load Balancing Manager has completed configuring the host, the host state should be listed as Converged. NORTEL External Distribution 46

48 Step 9 Adding Additional Hosts to the Cluster In the Network Load Balancing Manager application, right click on the cluster you just created (e.g. and select Add Host to Cluster. A new host can also be added to the cluster by selecting the Cluster menu and clicking on Add Host. NORTEL External Distribution 47

49 Step 10 Adding Labserver2 to the Cluster In the Connect window in the Host field, type in the name or IP Address of the second server that will be a member of the cluster. Click Connect and the Network Load Balancing Manager will attempt to contact the server. If successful, the Connection Status field should show Connected and a list of available Network Adaptors will be listed in the Interface name table. Select the Interface that is to participate in the cluster and click on Next. NORTEL External Distribution 48

50 Step 11 Modifying Labserver2 Host Parameters The Host Parameters window defines the Priority or Host ID for the cluster host instance, the unique IP Address bound to the Network Adaptor and the Initial host state. For our example server Labserver2 will be assigned as host 2. We will retain the IP Addressing that was initially assigned to the Network Adaptor and we will use the default state of Started. Click Finished NORTEL External Distribution 49

51 Once the second host has been successfully added to the cluster, the host state will change to Converged. NORTEL External Distribution 50

52 3.5 Ethernet Switch Configuration Example The following configuration example demonstrates how to configure a standalone Nortel Ethernet Stackable Switch to support a Microsoft Network Load Balancing cluster of servers running in unicast or multicast modes. In this example the Network Load Balancing cluster of servers and clients will be located on a single IP subnet (VLAN) which will represent a typical small office deployment. As described in previous sections, no special switch configuration is required, however for this example we will enable IGMP snooping and proxy on the switch to provide multicast flood suppression. Figure 3.5 ES T Example Topology ES T Configuration For this example we will configure an Ethernet Switch T as follows: 1. Configure a management IP address of /24 2. Enable IGMPv2 snooping and proxy to provide NLB multicast suppression From the Ethernet Switch Main Menu, select Command Line Interface to access the Nortel CLI. 1. At the CLI prompt, enter the configuration mode: T>enable T# configure terminal NORTEL External Distribution 51

53 2. Create a IP address on the Ethernet Switch for management: T(config)# ip address switch netmask Verify IP addressing: T (config)# show ip BootP Mode: BootP Disabled Configured In Use Last BootP Stack IP Address: Switch IP Address: Subnet Mask: Default Gateway: At the CLI prompt, enter the configuration mode: T>enable T# configure terminal 5. Enable IGMP snooping and proxy on VLAN 1: T(config)# vlan igmp 1 snooping enable T(config)# vlan igmp 1 proxy enable 6. Verify IGMP snooping and proxy are enabled on VLAN 1: T(config)# show vlan igmp 1 Snooping: Enabled Proxy: Enabled Robust Value: 2 Query Time: 125 seconds IGMPv1 Static Router Ports: NONE IGMPv2 Static Router Ports: NONE 7. Verify IGMP is suppressing the multicast flows to the server ports: T(config)# show vlan multicast membership 1 Multicast Group Address Port NORTEL External Distribution 52

54 3.6 ERS 1600 Configuration Example The following configuration example demonstrates how to configure a centralized Nortel Ethernet Routing Switch 1600 to support a multiple subnet environment where the Microsoft Network Load Balancing cluster of servers and clients are connected to a subtended Layer 2 switches and are placed in separate IP subnets (VLANs). Figure 3.6 ERS 1612G Example Topology ERS 1612G Configuration For the first step we will configure an Ethernet Routing Switch 1600 as follows: 1. Create VLAN 2 to support clients (VLAN 1 is enabled by default) 2. Enable 802.1Q tagging on ports Assign ports 1 2 to VLAN 1 4. Assign port 3 4 to VLAN 2 5. Assign a IP address of /24 to VLAN 1 6. Assign a IP address of /24 to VLAN 2 7. Force speed and duplex on ports 3 4 to 1000Mbps FDX to support the ES T 8. Create a Multi-Link Trunk with ports 1 2 to connect the ERS T server switch 9. Create a Multi-Link Trunk with ports 3 4 to connect the ES T client switch 10. Create a static ARP entry to support NLB multicast mode NORTEL External Distribution 53

55 Connect to the Ethernet Routing Switch 1600 and log into the CLI with the username rwa and the password rwa. 1. Create port based VLAN with a id 2 and name it VLAN2: PP1612G# create vlan VLAN2 vid 2 type port 2. Remove ports 3 24 from VLAN 1: PP1612G# config vlan default delete Add ports 1 2 to VLAN 1 and enable 802.1Q tagging: PP1612G# config vlan default add tagged Add ports 3 4 to VLAN 2 and enable 802.1Q tagging: PP1612G# config vlan VLAN2 add tagged Verify VLAN configuration: PP1612G# show vlan VID : 1 VLAN Name : default VLAN TYPE : port Protocol ID : UserDefinedPid : Encap : IP Subnet : Priority : Member ports : 1-2,mgmt_port Static ports : 1-2 Untagged ports : mgmt_port VID : 2 VLAN Name : VLAN2 VLAN TYPE : port Protocol ID : UserDefinedPid : Encap : IP Subnet : Priority : Member ports : 3-4 Static ports : 3-4 Untagged ports : Total Entries : 2 NORTEL External Distribution 54

56 6. Change the IP address for VLAN 1 to and set the subnet mask to : PP1612G# config ipif System ipaddress /24 7. Create a IP Interface named VLAN 2_IF, set the IP address to and the subnet mask to and tie it to the VLAN named VLAN2: PP1612G# create ipif VLAN2_IF /24 VLAN2 8. Verify IP Interface configuration: PP1612G# show ipif IP Interface Settings Interface Name : System IP Address : (MANUAL) Subnet Mask : VLAN Name : default Admin. State : Enabled Interface Status : Link DOWN Directed-Broadcast: Enabled Member Ports : 1-2,mgmt_port Interface Name : VLAN2_IF IP Address : (MANUAL) Subnet Mask : VLAN Name : VLAN2 Admin. State : Enabled Interface Status : Link DOWN Directed-Broadcast: Enabled Member Ports : 3-4 Total Entries : 2 9. Ports 3 4 will connect to a ES T so we will need to force the speed and duplex on the ports to 1000Mbps Full Duplex: PP1612G# config ports 3-4 speed 1000_full NORTEL External Distribution 55

57 10. Verify Ports 3 4 speed and duplex settings: PP1612G# show ports 3-4 Port Port Settings Connection Address State Speed/Duplex/FlowCtrl Speed/Duplex/FlowCtrl Learning Enabled 1000M/Full/Disabled Link Down Enabled 4 Enabled 1000M/Full/Disabled Link Down Enabled 11. Create Multi-Link Trunking group 1 and add ports 1-2: PP1612G# create link_aggregation group_id 1 PP1612G# config link_aggregation group_id 1 master_port 1 ports 1-2 PP1612G# config link_aggregation group_id 1 state enabled 12. Create Multi-Link Trunking group 2 and add ports 3-4: PP1612G# create link_aggregation group_id 2 PP1612G# config link_aggregation group_id 2 master_port 3 ports 3-4 PP1612G# config link_aggregation group_id 2 state enabled 13. Verify Multi-Link Trunking configuration: PP1612G# show link_aggregation Group ID : 1 Master Port : 1 Member Port : 1-2 Status : Enabled Flooding Port : 1 BPDU 8600 Interop : Disabled Group ID : 2 Master Port : 3 Member Port : 3-4 Status : Enabled Flooding Port : 3 BPDU 8600 Interop : Disabled NORTEL External Distribution 56