1-26
Cisco ASA Series CLI Configuration Guide
Chapter 1 Introduction to the Cisco ASA
Firewall Functional Overview
For multiple context mode, if you place the router behind the ASASM, you should only connect it to a
single context. If you connect the router to multiple contexts, the router will route between the contexts,
which might not be your intention. The typical scenario for multiple contexts is to use a router in front
of all the contexts to route between the Internet and the switched networks (see
).
Figure 1-2
MSFC/Router Placement with Multiple Contexts
Firewall Functional Overview
Firewalls protect inside networks from unauthorized access by users on an outside network. A firewall
can also protect inside networks from each other, for example, by keeping a human resources network
separate from a user network. If you have network resources that need to be available to an outside user,
such as a web or FTP server, you can place these resources on a separate network behind the firewall,
called a
demilitarized zone
(DMZ). The firewall allows limited access to the DMZ, but because the DMZ
only includes the public servers, an attack there only affects the servers and does not affect the other
inside networks. You can also control when inside users access outside networks (for example, access to
the Internet), by allowing only certain addresses out, by requiring authentication or authorization, or by
coordinating with an external URL filtering server.
When discussing networks connected to a firewall, the
outside
network is in front of the firewall, the
inside
network is protected and behind the firewall, and a
DMZ
, while behind the firewall, allows limited
access to outside users. Because the ASA lets you configure many interfaces with varied security
policies, including many inside interfaces, many DMZs, and even many outside interfaces if desired,
these terms are used in a general sense only.
Context A
Context B
Context C
VLAN 203
VLAN 202
VLAN 201
VLAN 100
Admin
Context
VLAN 200
VLAN 300
VLAN 303
VLAN 302
VLAN 301
MSFC/Router
Internet
Inside
Customer A
Inside
Customer B
Inside
Customer C
Admin
Network
Содержание 5505 - ASA Firewall Edition Bundle
Страница 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Страница 61: ...P A R T 1 Getting Started with the ASA ...
Страница 62: ......
Страница 218: ...1 56 Cisco ASA Series CLI Configuration Guide Chapter 1 Managing Feature Licenses Feature History for Licensing ...
Страница 219: ...P A R T 2 Configuring High Availability and Scalability ...
Страница 220: ......
Страница 358: ...1 22 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About Failover Failover Messages ...
Страница 403: ...P A R T 2 Configuring Interfaces ...
Страница 404: ......
Страница 499: ...P A R T 2 Configuring Basic Settings ...
Страница 500: ......
Страница 516: ...1 16 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Basic Settings Monitoring DNS Cache ...
Страница 533: ...P A R T 2 Configuring Objects and Access Lists ...
Страница 534: ......
Страница 558: ...1 4 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About Access Lists Where to Go Next ...
Страница 601: ...P A R T 2 Configuring IP Routing ...
Страница 602: ......
Страница 632: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Defining Route Maps Feature History for Route Maps ...
Страница 680: ...1 48 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring OSPF Feature History for OSPF ...
Страница 745: ...P A R T 2 Configuring Network Address Translation ...
Страница 746: ......
Страница 780: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Information About NAT Where to Go Next ...
Страница 844: ...1 32 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Twice NAT Feature History for Twice NAT ...
Страница 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Страница 846: ......
Страница 859: ...1 13 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Servers and the Local Database Configuring AAA ...
Страница 871: ...1 25 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Servers and the Local Database Configuring AAA ...
Страница 981: ...P A R T 2 Configuring Access Control ...
Страница 982: ......
Страница 994: ...1 12 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Access Rules Feature History for Access Rules ...
Страница 1028: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Management Access Feature History for Management Access ...
Страница 1054: ...1 26 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring AAA Rules for Network Access Feature History for AAA Rules ...
Страница 1060: ...1 6 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Web Cache Services Using WCCP Feature History for WCCP ...
Страница 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Страница 1062: ......
Страница 1093: ...P A R T 2 Configuring Application Inspection ...
Страница 1094: ......
Страница 1191: ...P A R T 2 Configuring Unified Communications ...
Страница 1192: ......
Страница 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Страница 1334: ......
Страница 1370: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring QoS Feature History for QoS ...
Страница 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Страница 1380: ......
Страница 1448: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Threat Detection Configuration Examples for Threat Detection ...
Страница 1474: ...1 18 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Filtering Services Monitoring Filtering Statistics ...
Страница 1475: ...P A R T 2 Configuring Modules ...
Страница 1476: ......
Страница 1504: ...1 28 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA IPS Module Feature History for the ASA IPS module ...
Страница 1528: ...1 24 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA CX Module Feature History for the ASA CX Module ...
Страница 1548: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the ASA CSC Module Feature History for the CSC SSM ...
Страница 1549: ...P A R T 2 Configuring VPN ...
Страница 1550: ......
Страница 1592: ...1 42 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring IPsec and ISAKMP Supporting the Nokia VPN Client ...
Страница 1612: ...1 20 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring L2TP over IPsec Feature History for L2TP over IPsec ...
Страница 1796: ...1 6 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring the PPPoE Client Using Related Commands ...
Страница 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Страница 1966: ......
Страница 1988: ...1 22 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring Logging Feature History for Logging ...
Страница 2002: ...1 14 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring NetFlow Secure Event Logging NSEL Feature History for NSEL ...
Страница 2036: ...1 34 Cisco ASA Series CLI Configuration Guide Chapter 1 Configuring SNMP Feature History for SNMP ...
Страница 2059: ...P A R T 2 System Administration ...
Страница 2060: ......
Страница 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Страница 2099: ...P A R T 2 Reference ...
Страница 2100: ......