1-5
Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring the Transparent or Routed Firewall
Information About the Firewall Mode
•
ARPs are allowed through the transparent firewall in both directions without an access list. ARP
traffic can be controlled by ARP inspection.
•
For Layer 3 traffic travelling from a low to a high security interface, an extended access list is
required on the low security interface. See
Chapter 19, “Adding an Extended Access Control List,”
for more information.
Allowed MAC Addresses
The following destination MAC addresses are allowed through the transparent firewall. Any
MAC address not on this list is dropped.
•
TRUE broadcast destination MAC address equal to FFFF.FFFF.FFFF
•
IPv4 multicast MAC addresses from 0100.5E00.0000 to 0100.5EFE.FFFF
•
IPv6 multicast MAC addresses from 3333.0000.0000 to 3333.FFFF.FFFF
•
BPDU multicast address equal to 0100.0CCC.CCCD
•
AppleTalk multicast MAC addresses from 0900.0700.0000 to 0900.07FF.FFFF
Passing Traffic Not Allowed in Routed Mode
In routed mode, some types of traffic cannot pass through the ASA even if you allow it in an access list.
The transparent firewall, however, can allow almost any traffic through using either an extended access
list (for IP traffic) or an EtherType access list (for non-IP traffic).
Non-IP traffic (for example AppleTalk, IPX, BPDUs, and MPLS) can be configured to go through using
an EtherType access list.
Note
The transparent mode ASA does not pass CDP packets packets, or any packets that do not have a valid
EtherType greater than or equal to 0x600. An exception is made for BPDUs and IS-IS, which are
supported.
Passing Traffic For Routed-Mode Features
For features that are not directly supported on the transparent firewall, you can allow traffic to pass
through so that upstream and downstream routers can support the functionality. For example, by using
an extended access list, you can allow DHCP traffic (instead of the unsupported DHCP relay feature) or
multicast traffic such as that created by IP/TV. You can also establish routing protocol adjacencies
through a transparent firewall; you can allow OSPF, RIP, EIGRP, or BGP traffic through based on an
extended access list. Likewise, protocols like HSRP or VRRP can pass through the ASA.
BPDU Handling
To prevent loops using the Spanning Tree Protocol, BPDUs are passed by default. To block BPDUs, you
need to configure an EtherType access list to deny them. If you are using failover, you might want to
block BPDUs to prevent the switch port from going into a blocking state when the topology changes.
See the
“Transparent Firewall Mode Requirements” section on page 9-14
for more information.
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 ...
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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 ...
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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 ...
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Страница 499: ...P A R T 2 Configuring Basic Settings ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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Страница 1093: ...P A R T 2 Configuring Application Inspection ...
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Страница 1191: ...P A R T 2 Configuring Unified Communications ...
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Страница 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
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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 ...
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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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