IBM AS/400e User Handbook Manual page 599

• TCP/UDP source port
• TCP/UDP destination port
• TCP/IP ack flag
• Secure or nonsecure port
There is a separate proxy server for each server application, such as Telnet, FTP, or HTTP
server. The support is provided in the firewall with no software change required on the client.
This is an implementation for "hiding internal information".
SOCKS is implemented in the firewall but requires cooperative SOCKS software on the client,
a "Socksified client". The SOCKS Server provides common support for all server applications
using it. This is the newer implementation for "hiding internal information" because it does not
require the overhead used by a proxy server, which should improve performance.
After installing a firewall to protect the internal secure network, isolate the Domain Name
Services that are accessible inside the secure network so that the internal network structure
is not visible from the outside.
The Mail Server works with the domain name server to relay mail between the internal or
secure mail server and other mail servers on the Internet using SMTP or SafeMail. The
secure mail server is isolated so that the internal network is not visible from the outside.
SafeMail Mail Relay allows secure access to multiple mail servers behind the firewall.
Beginning with OS/400 V4R4, mail is not stored on the firewall as it was with the previous
implementation of SafeMail. Mail is forwarded directly to the mail server responsible for
handling it. Internal mail addresses remain hidden from the Internet. SafeMail provides
anti-spamming capabilities.
When Firewall for AS/400 is used in conjunction with HTTP Server for AS/400 and one of the
Cryptographic Access Providers Licensed Programs, AS/400 systems attached to the
Internet can send and receive information from Internet users in a secure manner. The
firewall prohibits unwanted traffic from entering the internal secure network while the
Cryptographic Access Provider encrypts data that is exchanged on the Internet.
Several logging facilities are available with the Firewall. Also included is the capability to
export the log files to database tables for analysis using SQL queries.
For more information on the IBM Firewall for AS/400, access the firewall home page at:
http://www.as400.ibm.com/firewall
IBM Licensed Programs: Networking Products
IBM Licensed Programs: Networking Products
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