Configuration Decisions

How you configure TCP/IP beyond the most basic configuration depends on the following decisions:

• Whether a multiprocessor server can use this version of TCP/IP

  The TCP/IP stack distributes the connection across all processors uniformly resulting in packet processing on different processors in parallel. The TCP/IP stack has been multiprocessor (MP) enabled for processing TCP and UDP packets.

• Whether to use the computer as a router or an end node (that is, a host)

  The IP Packet Forwarding parameter, which controls IP packet routing, is enabled by default. This parameter permits your computer to operate as an IP router. When you want your computer to operate as an end node only, disable this parameter.

• Whether to use Routing Information Protocol (RIP), Open Shortest Path First (OSPF), or a mixed RIP-OSPF environment

  RIP and OSPF are IP routing protocols. If you already have IP routers in your network environment, use the same routing protocol they use. If your network currently has no other routers, use OSPF.

  To configure your router as a RIP router, see Configuring RIP.

  To configure your router as an OSPF router, see Configuring OSPF.

  To configure a mixed RIP-OSPF environment, refer to both of the preceding procedures.

• Whether to use static routes on a router

  Static routes are useful for reducing routing traffic, providing security, accessing isolated networks, and operating as backup routes on routers. Static routes are required for on-demand connections.

  To configure static routes on a router, see Configuring Static Routes for LANs.

• Whether to filter routes or various TCP/IP packets

  Enable filters when you want to do either of the following:

  • Control access to any services, such as File Transfer Protocol (FTP), on your network
  • Reduce the bandwidth consumed by routing traffic

  To configure TCP/IP filters, you must enable the Filtering Support parameter in INETCFG and then load the Filter Configuration utility (FILTCFG).

• Whether to configure router discovery

  Router discovery enables end nodes to find an IP router on their network. If your computer is operating as a router, it can advertise itself periodically as a router. If your computer is operating as an end node, it can send queries to locate a router.

  To configure router discovery, see Configuring Router Discovery.

• Whether to disable Address Resolution Protocol (ARP) or enable Proxy ARP

  ARP is a LAN protocol that maps Internet addresses to physical addresses. IP routers and end nodes use ARP to determine a destination node's physical address.

  An IP router using Proxy ARP replies to ARP requests it receives through an interface on behalf of an end node on a network attached to another interface.

  To change the default settings of ARP and Proxy ARP features, see Configuring ARP.

• Whether to enable the router to forward directed broadcasts

  A directed broadcast is a broadcast intended only for a subnet rather than all nodes on the network.

  To enable directed broadcast forwarding, see Configuring Directed Broadcast Forwarding.

• Whether to configure the router or end node as a BOOTP forwarder

  The BOOTP protocol enables end nodes to obtain an IP address at start-up time. If there is a BOOTP or Dynamic Host Configuration Protocol (DHCP) server on your internetwork, any IP routers that are configured to act as a BOOTP forwarder accept and forward BOOTP or DHCP requests to the server. The BOOTP or DHCP server then assigns an IP address to the end station.

  To configure BOOTP forwarding, see Configuring BOOTP Forwarding.

• Whether to configure multiple logical interfaces on a single board

  Using multiple logical interfaces enables you to bind more than one IP network to a LAN board. Each binding operates as a separate logical interface.

  To configure multiple logical interfaces on a board, see Configuring Multiple Logical Interfaces.

• Whether to use multihoming

  Multihoming enables an interface to be bound to multiple IP addresses on the same network. Multihoming can be used for all IP networks bound to a router, whether the networks are bound to on the same interface or different interfaces.

  The most common use of multiple addresses on the same network is to enable a Web server to operate as though it is several Web servers. In this application, each secondary IP address is used by a different virtual host on the same Web server. The Domain Name System (DNS) can be used to access these virtual hosts using unique hostnames.

  Multihoming is also commonly used with network address translation (NAT), the proxy server, and the virtual private network (VPN).

  To configure multihoming, see Configuring a Secondary IP Address.