No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

CX11x, CX31x, CX710 (Earlier Than V6.03), and CX91x Series Switch Modules V100R001C10 Configuration Guide 13

The documents describe the configuration of various services supported by the CX11x&CX31x&CX91x series switch modules The description covers configuration examples and function configurations.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Introduction to NLB Cluster Association

Introduction to NLB Cluster Association

Network Load Balance (NLB) is a Microsoft implementation of clustering and load balancing on Windows servers. Servers in an NLB group support load balancing and redundancy. When a server in the group fails, data can be quickly switched to other servers. To implement quick data switching, devices on the network must be able to forward service traffic to each server in the NLB group. Each server in the NLB group uses the same NLB algorithm to determine whether to process the service traffic.

NLB servers can work in unicast, multicast, and IGMP multicast mode. Currently, the device can only be connected to NLB servers working in unicast or multicast mode.

  • When NLB servers work in unicast mode, the virtual MAC address starts with 02BF.
  • When NLB servers work in multicast mode, the virtual MAC address starts with 03BF.

As shown in Figure 10-68, each server in the NLB group has its own IP address and MAC address. In addition, the servers share a virtual IP address and a virtual MAC address. Switch_1 functions as the access gateway and directly connects to the NLB group. Switch_1 needs to forward packets destined for the virtual IP address to all servers in the NLB group.

After servers in the NLB group receive ARP Request packets for the virtual MAC address from Switch_1, all the servers return ARP Reply packets. In the ARP Reply packets, the protocol source IP address is the virtual IP address and the protocol source MAC address is the virtual MAC address.

  • When NLB servers work in unicast mode, Switch_1 learns only one outbound interface (interface connecting Switch_1 to an NLB server) from the ARP entry matching the NLB group virtual IP address in the ARP table. Therefore, Switch_1 can forward packets destined for the virtual IP address to only one server in the NLB group.
  • When NLB servers work in multicast mode, Switch_1 does not learn ARP entries after receiving ARP Reply packets from NLB servers because the protocol source MAC address is a multicast MAC address. If you configure a static ARP entry by binding the virtual IP address to the virtual MAC address, only one outbound interface is specified. Therefore, Switch_1 can forward packets destined for the virtual IP address to only one server in the NLB group.

To resolve the preceding problems, you can deploy multi-interface ARP to allow Switch_1 to forward packets destined for the virtual IP address to all servers in the NLB group.

Figure 10-68 Typical networking diagram for multi-interface ARP

In multi-interface ARP, a static ARP entry is configured by binding the virtual IP address to the virtual MAC address, and MAC address entries are configured by binding the virtual MAC address to multiple outbound interfaces. When Switch_1 forwards packets destined for the virtual IP address, Switch_1 first searches for the ARP entry matching the virtual IP address to determine the virtual MAC address and the VLAN to which the NLB servers belong. Switch_1 then searches the MAC address table for multiple outbound interfaces based on the virtual MAC address and VLAN. Switch_1 forwards packets to each connected NLB server through the outbound interfaces.

Translation
Download
Updated: 2019-12-13

Document ID: EDOC1000041694

Views: 60644

Downloads: 3623

Average rating:
This Document Applies to these Products
Related Version
Related Documents
Share
Previous Next