56 | Dell EMC VxRail Appliance Operations Guide
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Table 4. VxRail traffic on 1GbE NICs
Enabling multicast
By default, a switch in a VxRail network floods multicast traffic in the broadcast domain or
VLAN. To mitigate this problem, vSphere services use IPv4 multicast (IGMP
Querying/Snooping) to prune multicast traffic so that only the nodes that need the traffic receive
the traffic, thereby improving performance.
Routers are registered to receive specific multicast traffic only. IPv4 also responds to topology-
change notifications. Without IGMP Querying/Snooping, multicast traffic is treated like a
broadcast transmission, which forwards packets to all ports on the network. IPv6 multicast
functions similarly, sending multicast traffic only to multicast members. IPv6 multicast needs to
be enabled on all ports used by the VxRail nodes. IPv4 multicast is required for vSAN. For
larger environments that span multiple switches, it is important that IPv4 and IPv6 multicast
traffic is passed between them. Beginning with VxRail 4.5 and vSAN 6.6, vSAN uses Unicast
rather than multicast.
Virtual machine and optional data services networks
When the system is installed and initialized, a minimum of one VLAN is configured for guest
virtual machines. Additional VLANS can be defined as required. Additional VLANs may be
required to support optional data services such as RP4VM and CloudArray. Consult the product
documentations for details.
Optional NIC configurations
Some VxRail models may be configured with optional additional PCI NIC cards. While these are
not managed by VxRail Manager, you can configure them using vSphere. These optional NICs
are used exclusively for VM and application traffic. The kernel ports used by vSAN should not
be configured to use these NIC ports.
Changing network configuration
During initial install and configuration, VLAN ID and IP addresses are configured based on the
network planning checklist. Consult with Dell EMC Professional services if you need to change
VLAN IDs or IP addresses of the ESXi hosts and data services.
Summary of Contents for VxRail Appliance
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