Cisco 500 Series, Руководство по настройке

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C H A P T E R
7-1
Cisco Security Appliance Command Line Configuration Guide
OL-12172-03
7
Configuring Interface Parameters
This chapter describes how to configure each interface (physical, redundant, or subinterface) for a name,
security level, and IP address.
•
For single context mode, the procedures in this chapter continue the interface configuration started
in
Chapter 5, “Configuring Ethernet Settings, Redundant Interfaces, and Subinterfaces.”
• For multiple context mode, the procedures in Chapter 5, “Configuring Ethernet Settings, Redundant
Interfaces, and Subinterfaces,” are performed in the system execution space, while the procedures
in this chapter are performed within each security context.
Note To configure interfaces for the ASA 5505 adaptive security appliance, see Chapter 4, “Configuring
Switch Ports and VLAN Interfaces for the Cisco ASA 5505 Adaptive Security Appliance.”
This chapter includes the following sections:
•
Security Level Overview, page 7-1
• Configuring Interface Parameters, page 7-2
•
Allowing Communication Between Interfaces on the Same Security Level, page 7-7
Security Level Overview
Each interface must have a security level from 0 (lowest) to 100 (highest). For example, you should
assign your most secure network, such as the inside host network, to level 100. While the outside
network connected to the Internet can be level 0. Other networks, such as DMZs can be in between. You
can assign interfaces to the same security level. See the
“Allowing Communication Between Interfaces
on the Same Security Level” section on page 7-7 for more information.
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.
For same security interfaces, there is an implicit permit for interfaces to access other interfaces on
the same security level or lower.