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Cisco ASA Series CLI Configuration Guide
Chapter 1 Information About Failover
Failover and Stateful Failover Links
Although you can configure the failover and failover state links on a port channel link, this port channel
cannot be shared with other firewall traffic.
Stateful Failover Link
To use Stateful Failover, you must configure a Stateful Failover link to pass all state information. You
have three options for configuring a Stateful Failover link:
•
You can use a dedicated Ethernet interface for the Stateful Failover link.
•
You can share the failover link.
•
You can share a regular data interface, such as the inside interface. However, this option is not
recommended.
Connect a dedicated state link in one of the following two ways:
•
Using a switch, with no other device on the same network segment (broadcast domain or VLAN) as
the failover interfaces of the ASA.
•
Using a crossover Ethernet cable to connect the appliances directly, without the need for an external
switch.
Note
When you use a crossover cable for the state link, if the interface fails, the link is brought down on both
peers. This condition may hamper troubleshooting efforts because you cannot easily determine which
interface failed and caused the link to come down.
The ASA supports Auto-MDI/MDIX on its copper Ethernet ports, so you can either use a crossover cable
or a straight-through cable. If you use a straight-through cable, the interface automatically detects the
cable and swaps one of the transmit/receive pairs to MDIX.
Enable the PortFast option on Cisco switch ports that connect directly to the ASA.
If you use a data interface as the Stateful Failover link, you receive the following warning when you
specify that interface as the Stateful Failover link:
******* WARNING ***** WARNING ******* WARNING ****** WARNING *********
Sharing Stateful failover interface with regular data interface is not
a recommended configuration due to performance and security concerns.
******* WARNING ***** WARNING ******* WARNING ****** WARNING *********
Sharing a data interface with the Stateful Failover interface can leave you vulnerable to replay attacks.
Additionally, large amounts of Stateful Failover traffic may be sent on the interface, causing
performance problems on that network segment.
Note
Using a data interface as the Stateful Failover interface is supported in single context, routed mode only.
In multiple context mode, the Stateful Failover link resides in the system context. This interface and the
failover interface are the only interfaces in the system context. All other interfaces are allocated to and
configured from within security contexts.
Note
The IP address and MAC address for the Stateful Failover link does not change at failover unless the
Stateful Failover link is configured on a regular data interface.
Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......