7-8
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter7 Starting Interface Configuration (ASA 5505)
Starting ASA 5505 Interface Configuration
Caution The ASA 5505 does not support Spanning Tree Protocol for loop detection in the network. Therefore
you must ensure that any connection with the ASA does not end up in a network loop.
Detailed Steps
Command Purpose
Step1 interface ethernet0/port
Example:
hostname(config)# interface ethernet0/1
Specifies the switch port you want to configure, where port is 0
through 7.
Step2 switchport access vlan number
Example:
hostname(config-if)# switchport access
vlan 100
Assigns this switch port to a VLAN, where number is the VLAN
ID, between 1 and 4090. See the “Configuring VLAN Interfaces”
section on page 7-6 to configure the VLAN interface that you
want to assign to this switch port. To view configured VLANs,
enter the show interface command.
Note You might assign multiple switch ports to the primary or
backup VLANs if the Internet access device includes
Layer 2 redundancy.
Step3 (Optional)
switchport protected
Example:
hostname(config-if)# switchport protected
Prevents the switch port from communicating with other
protected switch ports on the same VLAN.
You might want to prevent switch ports from communicating with
each other if the devices on those switch ports are primarily
accessed from other VLANs, you do not need to allow
intra-VLAN access, and you want to isolate the devices from each
other in case of infection or other security breach. For example, if
you have a DMZ that hosts three web servers, you can isolate the
web servers from each other if you apply the switchport
protected command to each switch port. The inside and outside
networks can both communicate with all three web servers, and
vice versa, but the web servers cannot communicate with each
other.
Step4 (Optional)
speed {auto | 10 | 100}
Example:
hostname(config-if)# speed 100
Sets the speed. The auto setting is the default. If you set the speed
to anything other than auto on PoE ports Ethernet 0/6 or 0/7, then
Cisco IP phones and Cisco wireless access points that do not
support IEEE 802.3af will not be detected and supplied with
power.
Step5 (Optional)
duplex {auto | full | half}
Example:
hostname(config-if)# duplex full
Sets the duplex. The auto setting is the default. If you set the
duplex to anything other than auto on PoE ports Ethernet 0/6 or
0/7, then Cisco IP phones and Cisco wireless access points that do
not support IEEE 802.3af will not be detected and supplied with
power.
Step6 no shutdown
Example:
hostname(config-if)# no shutdown
Enables the switch port. To disable the switch port, enter the
shutdown command.