H20790: Restrictions using the second Ethernet port - IBM Disk Systems


RETAIN tip: H20790


When using the second ethernet port on IBM DS3K/4K/5K subsystems, there are some restrictions that need to be adhered to. If the second ethernet port is improperly configured, then it is possible to lose access to the port or have an unexpected controller reboot.

Affected configurations

The system may be any of the following IBM servers:

  • DS4200 Storage Server, type 1814, any model
  • DS4700 Storage Server, type 1814, any model
  • DS4800 Storage Server, type 1815, any model
  • DS5020 Disk Controller (1814-20A), any model
  • DS5100 Storage Controller, type 1818, any model
  • DS5300 Storage Controller, type 1818, any model
  • IBM System Storage DS3512, type 1746, any model
  • IBM System Storage DS3524, type 1746, any model
  • IBM System Storage DS3950 Express, type 1814, any model

This tip is not software specific.

This tip is not option specific.


When setting up the network using dual Ethernet ports on IBM DS3K/4K/5K subsystems, keep the following restrictions in mind:

  1. Both Ethernet ports must use the same gateway address.

    Note: If DHCP is enabled on both ports, the Dynamic Host Configuration Protocol (DHCP) servers attached to the two (2) ports should be configured to supply the same gateway address. If the DHCP servers apply different gateway addresses, then the most recently obtained gateway address will be used for both ports.

  2. Regardless of whether or not you are using DHCP or static Internet Protocol (IP) addresses, the two (2) Ethernet ports must be on different subnets.

Additional information

This issue is due to a design limitation.

Applicable countries and regions


Document id:  MIGR-5086459
Last modified:  2011-03-01
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