Planning Volume 2, Control Workstation and Software Environment

Question 5: What type of network connectivity do you need?

In order to answer this question, you need to consult with your network administrator to decide how this system will connect into your existing computing network. Also consult with your hardware planner regarding which adapters work with the node types you are considering (see the book IBM RS/6000 SP: Planning Volume 1, Hardware and Physical Environment).

You might not have determined your system requirements quite enough yet to be able to fully answer all the questions you need to consider. But do start to think about them and know that you will have to come back to them and fill in all the network information when your physical layout plan is complete. Also, Planning your network configuration will help you understand the SP network capabilities.

Your answers for question 5 are applied in the collection of worksheets for Question 8: Which and how many nodes do you need?.

Questions to consider

Review the following questions to determine the type of network connectivity your organization needs:

• Do you currently have a TCP/IP network?
• Do you intend to connect that network to the SP Ethernet admin LAN and the control workstation? Only IPv4 networks are supported on the SP system. Some PSSP components tolerate IPv6 aliases for IPv4 network addresses but not with DCE, HACMP, HACWS, or an SP switch. For information about the SP system tolerating IPv6 aliases for IPv4 network addresses, see the appendix on the subject in the book PSSP: Administration Guide.
• |What type of physical Ethernet LAN do you require? The PSSP software |supports twisted pair (TP), thin Ethernet (BNC), and thick Ethernet (DIX) for |the SP Ethernet admin LAN.
• Do you have a TCP/IP address range? What is the address range and the subnet scheme? What subnet masks are employed? Will the address range be sufficient to cover the addresses of the SP nodes and control workstations? Remember to consider the future. For instance, you might start with a 10-node system but plan to grow to 100 nodes. Be sure to define an address range that is broad enough to accommodate your future needs.
• Do you have a domain name? If so, what is it? How are IP addresses resolved to names and vice versa? Do you have DNS, NIS, or /etc/hosts? How are your domain name servers configured?
• What is the topology of your TCP/IP network? Where do you intend to connect the |IBM pSeries or RS/6000 workstations and the nodes into the network?

  For the SP system and the control workstations, also consider the following:

• |The RS/6000 SP system or cluster of IBM pSeries or |RS/6000 nodes with a switch has a minimum of two networks, the SP Ethernet |administrative LAN that connects each node to the control workstation and the |switch network. With an SP Switch2, you can have two planes in the |switch network. The two networks must each be assigned unique TCP/IP |network addresses. The switch subsystem provides an optional aggregate |IP device abstraction for the SP Switch2 networks. This pseudo-device |driver enables you to address the two SP Switch2 planes with one IP |address. If you have a switch, you must plan for the switch |network.
• In addition to the SP Ethernet admin LAN and the switch network, additional communications adapters like ATM or FDDI are often installed in the nodes. In that case, separate TCP/IP network addresses need to be assigned. Have such networks been considered?
• What domain name will be assigned to the SP?
• What IP networks, addresses, subnet masks and default gateways will be assigned to the SP networks?
• |Do you want a firewalled SP system? See the document on this subject |at the Web address given in Finding documentation on the World Wide Web.
• Will nodes be configured as primary and secondary name servers?
• What SP-attached or clustered enterprise server considerations are there? If you plan to use a server that is otherwise already in use and connected to an IPv6 network, you must remove it from the IPv6 network before using it with the PSSP software. For more information about servers, see page ***.

Considering the SP Switch router

To provide higher bandwidth communications, an SP Switch Router can be connected to the SP Switch by the SP Switch Router Adapter. The SP Switch Router Adapter provides a high performance, full duplex interface between the SP Switch and the SP Switch Router.

Note:

|The SP Switch Router is not supported on the SP Switch2. |

When the SP Switch Router Adapter is installed in an SP Switch Router, it allows the SP Switch Router to be used as a networking gateway for the SP system. The SP Switch Router can be populated with additional adapters for standard network interfaces, including the types:

• Ethernet
• FDDI
• ATM
• SONET
• HIPPI
• HSSI

More than one SP Switch Router Adapter can be installed in an SP Switch Router. These SP Switch Routers can be connected to the same SP system, system partition, or to other SP systems. When multiple SP Switch Router Adapters are installed and connected to more than one SP system or system partition, they can be used to provide a high-bandwidth link between SP systems or system partitions and to provide the SP systems or system partitions with a shared set of interfaces to external networks.

Each SP Switch Router Adapter requires one available node switch port on the SP Switch that meets the criteria for valid extension node ports as described in Chapter 3, Defining the configuration that fits your needs. A 10 meter SP Switch cable and a 10 meter ground strap are provided (other lengths are available) for connecting the SP Switch Router Adapter, located in the SP Switch Router chassis, to the SP Switch.