Dell PowerVault NX3500 Administrator's Manual page 38

All-in-One High-Availability Option
In an all-in-one high availability option, the redundant switches host both
SAN or internal and client network traffic. The SAN or internal and client
cables are split between the redundant switches. Peer connections are always
back to back. It is recommended that you separate the SAN subnets using
virtual LANs.
38
Setting Up Your PowerVault NX3500 Solution