What is unicast and multicast in NLB?
What is unicast and multicast in NLB?
* MS NLB supports two configurations: unicast mode, or multicast mode. Unicast mode replaces the existing MAC address of all cluster members with a new cluster MAC address, which is shared by all nodes. Multicast mode adds the cluster MAC address to the node adapter, but also leaves the original one.
What is unicast NLB?
In unicast mode, NLB uses the NLB MAC address to replace the original hardware MAC address of each adapter in each node of the cluster. Because multiple adapters now have the same address, any physical switches in the network can no longer correctly maintain their MAC address tables.
What is Microsoft NLB?
The Network Load Balancing (NLB) feature distributes traffic across several servers by using the TCP/IP networking protocol. By combining two or more computers that are running applications into a single virtual cluster, NLB provides reliability and performance for web servers and other mission-critical servers.
How do I create a network load balancing cluster?
Step 1: Open Network Load Balancing Manager from the ‘Tools’ menu of the Server Manager. Step 2: In the Network Load Balancing Manager create a new cluster: Cluster > New. Step 3: In the New Cluster: Connect window enter the current server IP address into the Host field and click Connect.
How does NLB work in multicast mode?
In multicast mode, NLB assigns a layer-2 multicast address to the cluster adapter instead of changing the adapter’s station address. Multicast allows inter-host communication because it adds a layer two multicast address to the cluster instead of changing it.
Does NLB support IGMP snopping?
Without the IGMP option, NLB uses a locally administered Multicast MAC address with the format 03:BF: . Thus this is not an IANA-assingend multicast MAC address (01-00-5E), IGMP snopping cannot avoid the flooding of those frames throughout the entire VLAN, which is the only way a switch can handle such frames.
What are the requirements to configure an NLB cluster?
The network infrastructure must use a static ARP entry and a static MAC address table entry. The network switches must be capable of IGMP snooping. Additional advantage of automatic configuration. You can configure an NLB cluster in one of three operation modes: Unicast, multicast, or IMGP multicast.
Why ICMP is sent to only the NLB nodes?
IF I ping from the ASA to the Cluster IP, the ICMP is sent just to ALL the NLB nodes. 2) All frames originated from the NBL nodes has the unicast (physical) MAC address. 2) Other hosts in the same VLAN do not receive any broadcast related to this cluster (multicast is working)
