8-2
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter8 Completing Interface Configuration (Routed Mode)
Licensing Requirements for Completing Interface Configuration in Routed Mode
The level controls the following behavior:
Network access—By default, there is an implicit permit from a higher security interface to a lower
security interface (outbound). Hosts on the higher security interface can access any host on a lower
security interface. You can limit access by applying an access list to the interface.
If you enable communication for same security interfaces (see the “Allowing Same Security Level
Communication” section on page8-15), there is an implicit permit for interfaces to access other
interfaces on the same security level or lower.
Inspection engines—Some application inspection engines are dependent on the security level. For
same security interfaces, inspection engines apply to traffic in either direction.
NetBIOS inspection engine—Applied only for outbound connections.
SQL*Net inspection engine—If a control connection for the SQL*Net (formerly OraServ) port
exists between a pair of hosts, then only an inbound data connection is permitted through the
ASA.
Filtering—HTTP(S) and FTP filtering applies only for outbound connections (from a higher level
to a lower level).
If you enable communication for same security interfaces, you can filter traffic in either direction.
established command—This command allows return connections from a lower security host to a
higher security host if there is already an established connection from the higher level host to the
lower level host.
If you enable communication for same security interfaces, you can configure established commands
for both directions.

Dual IP Stack (IPv4 and IPv6)

The ASA supports the configuration of both IPv6 and IPv4 on an interface. You do not need to enter any
special commands to do so; simply enter the IPv4 configuration commands and IPv6 configuration
commands as you normally would. Make sure you configure a default route for both IPv4 and IPv6.
Licensing Requirements for Completing Interface Configuration in Routed Mode