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Dell EMC VxRail Multirack Deployment Guide
Configure network interfaces for witness traffic
In VMware vSAN 6.7U1 and later, witness traffic can be separated from data traffic. vSAN data traffic requires
a low-latency, high-bandwidth link. Witness traffic can use a high-latency, low-bandwidth, and routable link.
To separate data traffic from witness traffic, configure a dedicated VMkernel network adapter for vSAN
witness traffic.
1. Open an SSH connection to the first VxRail node, for example
sfo01w01vxrail01
.
2. Use the
esxcli network ip interface ipv4 get
command to determine which VMkernel
network adapter is used for management traffic. In this Deployment Guide management traffic for the
VxRail nodes uses the 172.16.31.0/24 subnet.
[root@sfo01w01vxrail01:~]
esxcli network ip interface ipv4 get
Name IPv4 Address IPv4 Netmask IPv4 Broadcast Address Type Gateway
---- ------------- ------------- -------------- ------------ ------
vmk2 172.16.31.101 255.255.255.0 172.16.31.255 STATIC 0.0.0.0
vmk0 0.0.0.0 0.0.0.0 0.0.0.0 NONE 0.0.0.0
vmk3 172.16.33.101 255.255.255.0 172.16.33.255 STATIC 0.0.0.0
vmk4 172.16.32.101 255.255.255.0 172.16.32.255 STATIC 0.0.0.0
vmk1 169.254.0.2 255.255.255.0 169.254.0.255 STATIC 0.0.0.0
3. Use the esxcli vsan network ip add command to configure the management VMkernel network
adapter to support witness traffic.
[root@sfo01w01vxrail01:~]
esxcli vsan network ip add -i vmk2 -T=witness
4. Use the
esxcli vsan network list
command to verify the new network configuration. Traffic
Type should list
witness
.
[root@sfo01w01vxrail01:~]
esxcli vsan network list | sed ‘1,/vmk2/d’
IP Protocol: IP
Interface UUID: 0c2a425c-ae19-5c96-dc9d-000af7f61ba0
Agent Group Multicast Address: 224.2.3.4
Agent Group IPv6 Multicast Address: ff19::2:3:4
Agent Group Multicast Port: 23451
Master Group Multicast Address: 224.1.2.3
Master Group IPv6 Multicast Address: ff19::1:2:3
Master Group Multicast Port: 12345
Host Unicast Channel Bound Port: 12321
Multicast TTL: 5
Traffic Type: witness
5. Repeat steps 1 through 4 for all remaining VxRail nodes.
Figure 20 shows the vSphere Client and the management VMkernel network interface is now enabled for
vSAN Witness traffic but not vSAN traffic. Do no enable the interface for vSAN traffic in the vSphere client.