System information

5500 Express IP Control Unit
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• The AS/400 system is connected through the WAN interface of the 2210
router. LAN is connected to the 2210 router and existing 5494 with twinax
workstations initially connected to the 5494 migrating to the IBM 5500
control unit.
C.3.0.1 Gateways and IP Addresses
As part of planning the installation of your 5500 control unit, determine the
range of addresses to be used by each network port of the 5500 control unit.
The twinax port allows up to 56 twinax-attached workstations to exploit the
TCP/IP protocol for access to network resources.
C.3.0.2 Subnetting
The 5500 control unit is unique because it allows you to use the subnetting of
an address space to define the addresses that can be used for the twinax
workstations without making subnet mask or default router changes to
existing LAN workstation or router configurations.
The 5500 control unit forwards IP packets, allowing all devices attached to the
5500 control unit to communicate with each other. It is not necessary to
configure a default router for devices attached to the 5500 control unit. Any
TCP request that is sent to an IP address in the network associated with any
port of the 5500 control unit is routed to that port. The 5500 control unit
implements an extended ARP (Address Resolution Protocol) agent to send
packets to twinax-attached TCP/IP workstations based on the twinax port
using a subnet of the network assigned to the LAN port 0 of the 5500 control
unit . If the destination IP address is outside the range of addresses known to
the 5500 control unit (or any default gateways configured for the workstation),
then the request fails.
If a LAN-attached device performs the function of a router to the Internet, the
IP address of that device should be used as the default gateway for that
network segment. This action grants Internet access to all workstations
attached to the 5500 control unit provided the address space used by those
workstations is properly coordinated so that your domain is known to the
Internic domain name server.
C.3.1 Installing the IBM 5500 into an Existing Network
One of the most common applications of the IBM 5500 control unit is to allow
existing twinax workstations that are remotely connected to an AS/400
system through a 5494 control unit, to be properly migrated to the IBM 5500
control unit. This application expands their use to the new e-business
applications. Under this circumstance, or for any other application where the
IBM 5500 Unit is placed on an existing LAN, you must decide whether to