In the following example we will configure the interface fast Ethernet 0/9  to default configuration

Current Configuration for fast Ethernet 0/9  

ITKE-Cisco#sho running-config interface fastEthernet 0/9

Building configuration…

Current configuration : 85 bytes

!

interface FastEthernet0/9

 switchport access vlan 100

 switchport mode access

end

ITKE-Cisco

Now we will configure the fast Ethernet 0/9 to default configuration using the following command

“default interface fastEthernet 0/9” 

ITKE-Cisco#configure t

Enter configuration commands, one per line.  End with CNTL/Z.

ITKE-Cisco(config)#default interface fastEthernet 0/9

Interface FastEthernet0/6 set to default configuration

ITKE-Cisco(config)#

Running configuration for fast Ethernet 0/9 after configuring to default settings

ITKE-Cisco#sho running-config interface fastEthernet 0/9

Building configuration…

Current configuration : 68 bytes

!

interface FastEthernet0/9

 switchport mode dynamic desirable

end

ITKE-Cisco#

Using the Cisco Security Device Manager (SDM) Firewall and ACL task section , you can create new Firewall and ACL.

The Cisco Security Device Manager (SDM) offers wizard to create either a Basic Firewall or an Advance Firewall. Now you are thinking what is the difference? The Basic Firewall won’t allow you to configure a DMZ zone where as the advance firewall does.

Th below figure explains how the basic firewall Configuration Wizard applies its template policy to the inside and outside interfaces. The wizard will give you the opportunity to which interface is which. The new policy will inspect TCP, UDP and other protocols that travel from inside to outside zone. It will block IM, P2P, MSN, Yahoo and AOL  IM traffic. It will also deny any unsolicited traffic coming on to the outside interface Figure B

Click Next, which will take you to the basic firewall Interface Configuration screen, as seen in figure B. This is where you can select which interface will be the inside and which will be the outside.

After you have made your selection, click Next. This takes you to the Basic firewall Security Configuration screen, as shown in figure C. Choose the level of Security for the firewall: High, Medium, or Low.

I choose Medium Security and clicked the preview commands button to review the commands this settings would apply.Figure C

When you see the output, you are pleased as you didn’t have to type all those commands manually

Figure D

Click Next. This takes you to the Basic Firewall Domain Name Server Configuration Screen, as shown in figure D. Specify the primary & secondary DNS server, and click Next. The Firewall Configuration summary screen sums up our choices as shown in figure E. Then click Finish.

Figure E

After successful completion of the above mentioned steps you can always review the changes as shown in figure F by clicking Edit Firewall Policy tab

Figure F