Ibm Firewall For As/400 V4R4, 5769-Fw1 - IBM AS/400e User Handbook Manual

IBM Licensed Programs: Networking Products

IBM Firewall for AS/400 V4R4, 5769-FW1

On 15 February 2000, IBM announced that the IBM Firewall for AS/400 (5769-FW1) product
will be supported with its current capability until 31 May 2001. This product will not be
enhanced beyond its current V4R4 capability and will be withdrawn from marketing on
29 December 2000. We recommend that customers running the IBM Firewall for AS/400
should plan to implement an alternative solution. V4R5 of AS/400 will be the final release to
support the IBM Firewall for AS/400. See the white paper at
http://www.as400.ibm.com/products/firewall/FW_Whitepaper.pdf
network security and alternative firewall solutions.
A firewall is a blockade between a secure, internal private network, and another non-secure
network such as the Internet. A firewall has two jobs:
• It lets users in the internal network use authorized resources that are located on the
outside network.
• It keeps unauthorized users who are outside the internal network from using resources
on the network.
IBM Firewall for AS/400 enables an Integrated Netfinity Server to function as a firewall on
OS/400 V4 systems. This application-proxy-based firewall, enables the Web server and other
functions on the main AS/400 processor to be used safely. Since the firewall runs on a
separate processor, attacks against the firewall do not affect the AS/400 system's
performance. Since the firewall has separate storage, attackers cannot access AS/400 data.
The OS/400 TCP/IP stack is completely independent of the TCP/IP stack on the Integrated
Netfinity Server.
Firewall for AS/400 helps protect the company's internal network in the following ways:
• It allows authorized users to move through the firewall to the unsecured network while
keeping unauthorized users from crossing the firewall into the secured network.
• It prevents the outside world from seeing the structure of the internal network.
• It allows mail to flow in and out of the internal secure network while hiding the network
address.
• It allows the establishment of Virtual Private Networks (VPN) that allow encrypted data
to flow between firewalls to safeguard data transported across the Internet.
The Internet Protocol (IP) packet filter provides the basic protection mechanism for the
firewall. The packet filter is a set of rules that limits IP packet flow into or out of the secure
network. It is possible to filter on any of the following fields in the IP packet header:
• Server IP address and mask
• Destination IP address and mask
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