Reference Guide

Figure 3. Network topology for a stretched cluster (basic)

High throughput configuration

In this topology we use two 25 GbE and one 1/10 GbE/25 GbE NICs for each host to configure a high throughput stretched

cluster. One NIC is dedicated for intra-site RDMA traffic, similar to a standalone Storage Spaces Direct environment. The

second NIC is used for replica traffic. SMB Multichannel is used to distribute traffic evenly across both replica adapters

and it increases network performance and availability. SMB Multichannel enables the use of multiple network connections

simultaneously, and facilitates the aggregation of network bandwidth and network fault tolerance when multiple paths are

available. For more information, see Manage SMB Multichannel.

The Set-SRNetworkConstraint cmdlet is used to ensure replica traffic flows only through the dedicated interfaces and not

through the management interface. Run this cmdlet once for each volume.

IP Address schema

The following table shows the IP Address schema:

Table 5. IP Address schema

Site A Site B Type of traffic

Management 192.168.100.0/24 192.168.200.0/24 L2/L3

Intra-site Storage (RDMA) - 1 192.168.101.0/24 192.168.201.0/24 L2

Intra-site Storage (RDMA) - 2 192.168.102.0/24 192.168.202.0/24 L2

Replica - 1* 192.168.111.0/24 192.168.211.0/24 L2/L3

Replica - 2* 192.168.112.0/24 192.168.212.0/24 L2/L3

VMNetwork As per customer environment As per customer environment L2/L3

Cluster IP 192.168.100.100 192.168.200.100 L2

*Static routes are needed on all hosts on both sites to ensure the 192.168.111.0/24 network can reach 192.168.211.0/24 and the

192.168.112.0/24 network can reach 192.168.212.0/24. Static routes are needed in this network topology because we have three

network pipes between Site A and Site B. Network traffic on Management uses the default gateway to traverse the network,

while Replica network uses static routes on the hosts to reach the secondary site. If your ToR switches do not have BGP

configured, static routes are needed on them also.

Solution deployment