System information

VNX™ System Operations86 of 114 Release 7.0
Avoid private LAN IP address conflicts
VNX servers use a private LAN for communication between the Control Stations
and Data Movers or blades. This LAN is sometimes also called a local or internal
LAN. By default, this private LAN uses IP addresses in the following three subnets:
◆ 128.221.252.nnn — This subnet is the primary private LAN. For the NS series
servers, this LAN connects to the LAN switch on the Control Station 0 tray
assembly.
◆ 128.221.253.nnn — This subnet is the secondary (or backup) private LAN. For
the NS series server with two Control Stations, the secondary LAN connects to
the LAN switch on the Control Station 1 tray assembly. For a single Control
Station NS series server, it shares the same network as the primary private
LAN, which uses the LAN switch on the Control Station 0 tray assembly.
◆ 128.221.254.nnn — This subnet is used for the Intelligent Platform
Management Interface (IPMI) connection between two Control Stations. IPMI
enables one Control Station to restart the other. The subnet consists of a
crossover cable connected between ports on the two Control Stations. This
subnet is not used for single Control Station servers.
Although the VNX private LAN does not connect to the public LAN, the Data
Movers (or blades) and Control Stations do connect to both the private and public. If
you are using these default subnet addresses in the public network, the VNX
equipment installer gave the VNX private LAN new addresses at installation time.
Ensure that you have these new addresses.
!
CAUTION
!
To prevent server disruption, do not connect the private LAN Ethernet switch to any
other network, network device, or host.
If you have more than one VNX server, each server can have the same set of
private LAN addresses. A conflict occurs only when the same subnet exists in both
the public and private LANs.
If you change the network configuration after the VNX server is installed, avoid
using the VNX private LAN subnets. If you must use them, reconfigure the VNX
private LAN to use different subnet addresses.
If you still have questions after reading this section, contact the EMC Customer
Service for assistance to avoid creating conflicting subnets.