Reference Guide

routes are needed on the L2/L3 to ensure that the Replica networks reach the intended destination. Subsequent sections of
this guide provide more information about the expectations of customer networking teams.
A stretched cluster environment has two storage pools, one per site. In both topologies described in the preceding section,
storage traffic requires Remote Direct Memory Access (RDMA) to transfer data between nodes within the same site. Because
Storage and Replica traffic produces heavy throughput on an all-flash or NVMe configuration, we recommend that you put
Storage traffic on separate redundant physical NICs.
This table shows the types of traffic, the protocol used, and the recommended bandwidth:
Table 1. Types of traffic
Types of traffic Protocol used Recommended bandwidth
Management TCP 1/10/25 Gb
Replica TCP 1/10/25 Gb
Intra-site storage RDMA 10/25 Gb
Compute Network TCP 10/25 Gb
Here are some points to consider about network configuration:
● Management traffic uses Transmission Control Protocol (TCP). Because management traffic uses minimal bandwidth, it can
be combined with Storage Replica traffic or even use the LOM, OCP or rNDC ports.
● VM Compute traffic can be combined with management traffic.
● Inter-site Live Migration traffic will use the same network as Storage Replica.
● Storage Replica uses TCP as RDMA is not supported for replica traffic over L3 or WAN links. Depending on the bandwidth
and latency between sites and the throughput requirements of the cluster, consider using separate redundant physical NICs
for Storage Replica traffic.
Solution overview
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