1-4
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Connection Settings
Licensing Requirements for Connection Settings
Inspection Overview” section on page 1-30
for more detailed information about the stateful firewall.
TCP packets that match existing connections in the fast path can pass through the ASA without
rechecking every aspect of the security policy. This feature maximizes performance. However, the
method of establishing the session in the fast path using the SYN packet, and the checks that occur in
the fast path (such as TCP sequence number), can stand in the way of asymmetrical routing solutions:
both the outbound and inbound flow of a connection must pass through the same ASA.
For example, a new connection goes to ASA 1. The SYN packet goes through the session management
path, and an entry for the connection is added to the fast path table. If subsequent packets of this
connection go through ASA 1, then the packets will match the entry in the fast path, and are passed
through. But if subsequent packets go to ASA 2, where there was not a SYN packet that went through
the session management path, then there is no entry in the fast path for the connection, and the packets
are dropped.
shows an asymmetric routing example where the outbound traffic goes through
a different ASA than the inbound traffic:
Figure 1-1
Asymmetric Routing
If you have asymmetric routing configured on upstream routers, and traffic alternates between two
ASAs, then you can configure TCP state bypass for specific traffic. TCP state bypass alters the way
sessions are established in the fast path and disables the fast path checks. This feature treats TCP traffic
much as it treats a UDP connection: when a non-SYN packet matching the specified networks enters the
ASA, and there is not an fast path entry, then the packet goes through the session management path to
establish the connection in the fast path. Once in the fast path, the traffic bypasses the fast path checks.
Licensing Requirements for Connection Settings
ISP A
Inside
network
Outbound?Traffic
Return?Traffic
ISP B
251155
Security
appliance 1
Security
appliance 2
Model
License Requirement
All models
Base License.
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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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Страница 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Страница 2099: ...P A R T 2 Reference ...
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