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In Multicast NLB mode, configure a
static ARP configuration
command to associate the cluster IP address with a multicast
cluster MAC address.
With Multicast NLB mode, the data forwards to all the servers based on the port specified using the following Layer 2 multicast
command in CONFIGURATION MODE:
mac-address-table static <multicast_mac> multicast vlan <vlan_id> output-range <port1>,
<port2>
Limitations of the NLB Feature
The following limitations apply to switches on which you configure NLB:
•
The NLB Unicast mode uses switch flooding to transmit all packets to all the servers that are part of the VLAN. When a large
volume of traffic is processed, the clustering performance might be impacted in a small way. This limitation is applicable to
switches that perform unicast flooding in the software.
•
The
ip vlan-flooding
command applies globally across the system and for all VLANs. In cases where NLB is applicable and
ARP replies contain a discrepancy in the Ethernet SHA and ARP header SHA frames, a flooding of packets over the relevant
VLAN occurs.
•
The maximum number of concurrent clusters that is supported is eight.
Microsoft Clustering
Microsoft clustering allows multiple servers using Microsoft Windows to be represented by one MAC address and IP address to
provide transparent failover or balancing. Dell Networking OS does not recognize server clusters by default; you must configure it to
do so. When an ARP request is sent to a server cluster, either the active server or all the servers send a reply, depending on the
cluster configuration. If the active server sends a reply, the Dell switch learns the active server’s MAC address. If all servers reply, the
switch registers only the last received ARP reply, and the switch learns one server’s actual MAC address; the virtual MAC address is
never learned. Because the virtual MAC address is never learned, traffic is forwarded to only one server rather than the entire
cluster, and failover and balancing are not preserved.
To preserve failover and balancing, the switch forwards the traffic destined for the server cluster to all member ports in the VLAN
connected to the cluster. To ensure that this happens, you must configure the
ip vlan-flooding
command on the Dell switch
when you configure the Microsoft cluster. The server MAC address is given in the Ethernet frame header of the ARP reply, while the
virtual MAC address representing the cluster is given in the payload. Then, all the traffic destined for the cluster is flooded out of all
member ports. Because all the servers in the cluster receive traffic, failover and balancing are preserved.
Enable and Disable VLAN Flooding
•
The older ARP entries are overwritten whenever newer NLB entries are learned.
•
All ARP entries, learned after you enable VLAN flooding, are deleted when you disable VLAN flooding, and RP2 triggers an ARP
resolution. Disable VLAN flooding with the
no ip vlan-flooding
command.
•
When you add a port to the VLAN, the port automatically receives traffic if you enabled VLAN flooding. Old ARP entries are not
deleted or updated.
•
When you delete a member port, its ARP entries are also deleted from the content addressable memory (CAM).
•
Port channels in the VLAN also receive traffic.
•
There is no impact on the configuration from saving the configuration.
•
If you enable VLAN flooding, it displays in the
show running-config
command output that displays the
ip vlan-
flooding
CLI configuration. This is the only output where you see the VLAN flooding status (enabled or disabled).
Microsoft Network Load Balancing
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Содержание S4048-ON
Страница 1: ...Dell Configuration Guide for the S4048 ON System 9 9 0 0 ...
Страница 146: ...Figure 14 BFD Three Way Handshake State Changes 146 Bidirectional Forwarding Detection BFD ...
Страница 477: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 477 ...
Страница 480: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command 480 Link Aggregation Control Protocol LACP ...
Страница 481: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 481 ...
Страница 522: ...Figure 87 Configuring Interfaces for MSDP 522 Multicast Source Discovery Protocol MSDP ...
Страница 523: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 523 ...
Страница 524: ...Figure 89 Configuring PIM in Multiple Routing Domains 524 Multicast Source Discovery Protocol MSDP ...
Страница 528: ...Figure 91 MSDP Default Peer Scenario 1 528 Multicast Source Discovery Protocol MSDP ...
Страница 529: ...Figure 92 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 529 ...
Страница 530: ...Figure 93 MSDP Default Peer Scenario 3 530 Multicast Source Discovery Protocol MSDP ...
Страница 633: ...Policy based Routing PBR 633 ...
Страница 777: ...Figure 119 Single and Double Tag TPID Match Service Provider Bridging 777 ...
Страница 778: ...Figure 120 Single and Double Tag First byte TPID Match 778 Service Provider Bridging ...