C H A P T E R
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Firewall Mode Overview
This chapter describes how the firewall works in each firewall mode. To set the firewall mode, see the
“Setting Transparent or Routed Firewall Mode” section on page 2-5
.
This chapter includes the following sections:
•
Routed Mode Overview, page 15-1
•
Transparent Mode Overview, page 15-6
Routed Mode Overview
In routed mode, the security appliance is considered to be a router hop in the network. It can use OSPF
or RIP (in single context mode). Routed mode supports many interfaces. Each interface is on a different
subnet. You can share interfaces between contexts.
This section includes the following topics:
•
IP Routing Support, page 15-1
•
How Data Moves Through the Security Appliance in Routed Firewall Mode, page 15-1
IP Routing Support
The security appliance acts as a router between connected networks, and each interface requires an
IP address on a different subnet. In single context mode, the routed firewall supports OSPF and RIP.
Multiple context mode supports static routes only. We recommend using the advanced routing
capabilities of the upstream and downstream routers instead of relying on the security appliance for
extensive routing needs.
How Data Moves Through the Security Appliance in Routed Firewall Mode
This section describes how data moves through the security appliance in routed firewall mode, and
includes the following topics:
•
An Inside User Visits a Web Server, page 15-2
•
An Outside User Visits a Web Server on the DMZ, page 15-3
•
An Inside User Visits a Web Server on the DMZ, page 15-4
Summary of Contents for 500 Series
Page 38: ...Contents xxxviii Cisco Security Appliance Command Line Configuration Guide OL 12172 03 ...
Page 45: ...P A R T 1 Getting Started and General Information ...
Page 46: ......
Page 277: ...P A R T 2 Configuring the Firewall ...
Page 278: ......
Page 561: ...P A R T 3 Configuring VPN ...
Page 562: ......
Page 891: ...P A R T 4 System Administration ...
Page 892: ......
Page 975: ...P A R T 5 Reference ...
Page 976: ......