TMS zl Module Planning and Implementation Guide 2009-08

Table Of Contents
Page 16
7.1.1 Firewall
Typical controls implemented by firewalls at the perimeter include, but are, of
course, not limited to:
Performing one-to-one NAT from registered, publicly routable IP
addresses in the External zone to private, non-publicly-routable IP
addresses for the Web Server, FTP Server and Proxy E-Mail Server in the
DMZ zone
Permitting Simple Mail Transfer Protocol (SMTP) traffic from the
External zone to the Proxy E-Mail Server in the DMZ zone.
Allowing File Transfer Protocol (FTP) traffic from the External zone to
the FTP Server in the DMZ zone.
Permitting the Hyper Text Transfer Protocol (HTTP) and HTTP Secure
(HTTPS) traffic from the External zone to the Web Server in the DMZ
zone
Denying all other traffic from the External zone from entering either the
DMZ or Internal zones
Allowing SMTP traffic from the Proxy E-Mail Server in the DMZ Zone
to the internal E-Mail Server in the Internal zone.
Permitting Structured Query Language (SQL) traffic from the Web
Server in the DMZ Zone to the Database Server in the Internal zone
Prohibiting all other traffic from the DMZ zone from entering either the
Internal or External zones
Performing many-to-one or many-to-many NAT from private, non-
publicly-routable IP addresses in the Internal zone to registered, publicly
routable IP addresses in the External zone
Using port maps to map HTTP traffic on non-standard ports (ie.
TCP/8000) to the HTTP service so it will be examined by IPS as HTTP
traffic
Allowing HTTP and HTTPS traffic from the Internal zone to the DMZ
and External zones
Permitting Simple Network Management Protocol (SNMP) traffic from
the Management Server in the Internal zone to the DMZ zone
Denying all other traffic from the Internal zone to the DMZ and External
zones