Are you unable to boot your Windows 7 or Windows Vista operating system-based computer, after making it dual-boot with an earlier version of Windows operating system? Do you encounter error when your system tries to read disk? This behavior of Windows may occur due to various compatibility issues and make your system unusable. At this point, you can not access your hard drive partitions and encounter partition loss situations. In order to recover lost partitions in such circumstances, Windows Data Recovery is required.

As a practical example, you may come below issues after installing an earlier version of MS Windows on a Windows Vista or Windows 7-based machine in dual-boot configuration:

Windows Vista does not boot after making your system dual-boot. Only earlier version of Windows boots up.

When you install an extra instance of Windows XP on a system, which has Windows Vista and Windows XP in dual-boot configuration, the below error message occurs.
“Disk read error has occurred.”

This behavior make your system inaccessible. To recover lost partitions in such cases, it becomes essential to find the cause of this problem and perform Windows Data Recovery by sorting it out.

Reason

This behavior of Windows operating system occurs as earlier versions of MS Windows are not compatible with Windows Vista boot method. Vista employs a new BCD (Boot Configuration Database) store. The BCD includes a boot menu and the information about the operating system, which are installed on your computer. Thus, the Boot.ini file which is from earlier version of Windows can not be used for booting up Windows Vista.

Resolution

You can try out the following things to work around this problem:

Use the Bootsect.exe for restoring Windows Vista Master Boot Record (MBR) and boot code, which transfers control to Windows Boot Manager (WBM) program.

Use Bcdedit.exe for creating a manual entry in BCD Boot.ini file in earlier version of Windows.

Reboot your system.

If the above method does not work, you need to format your hard drive and reinstall Windows Vista. In this case, you will lose all your hard drive partitions and need to Recover Partitions.

The make it quite easy to retrieve lost hard drive partitions. The software are able to handle all types of partition loss situations, using advanced scanning methods.

Stellar Phoenix Windows Data Recovery is the best made software that provides assured recovery of lost Windows partitions. It recovers FAT16, FAT32, VFAT, NTFS, and NTFS5 file system partitions. The software is designed for Microsoft Windows 7, Vista, 2003, XP, and 2000.

Firewalls are used to create control points on the border security of the networks. It can be either installed as a software program in a computer or it can be coupled with a separate hardware like router software. A good professional expertise helps in proper setup and configuration of firewall.

Firewall obstructs incoming and outgoing traffic from your computer, but if you want to have a clever watch on hackers who does not leave any chance to steal your personal information, then it is necessary that your firewall must be fully activated. Guidance from a certified technician helps to optimize your firewall security and you can fully assured for the safety of your data.

There are lot of advantages with using firewalls like security for both inbound and outbound traffic,  windows firewall comes with the operating system and is highly efficient, proprietary firewalls ( that comes with their own operating systems) provides high level of security, response time is very high in case of high end firewalls etc. All these features will be easily available for the users when they use the services of a certified technician to configure firewall.

A firewall allows you to open ports you wish to use and block other ports you might not require. Sometimes you have a need for addition of an instant messenger or any multiplayer game, in that case you have to configure firewall and allow this type of traffic. However you must keep in mind that addition of functionality reduces the security so try that you only add any functionality if there is an urgent requirement for that.

A firewall is very important for your system because it save the system from outside attacks and retains the safety of your computer. There are many companies in the market today that provide remote computer support for firewall setup and firewall configuration. Choosing a good technician in this field needs some research but be sure that you will hire the best one in the industry if you are really concerned about the safety and durability of your system.

A Cisco ASA security appliance has four main administrative access modes:

Monitor Mode:
Displays the monitor> prompt. A special mode that enables you to update the image over the network or to perform password recovery. While in the monitor mode, you can enter commands to specify the location of a TFTP server and the location of the software image or password recovery binary image file to download. You access this mode by pressing the “Break” or “ESC” keys immediately after powering up the appliance. Unprivileged Mode:
Displays the > prompt. Available when you first access the appliance. If the appliance is a Cisco PIX 500 series, the prompt for unprivileged mode is pixfirewall> and if the appliance is the new Cisco ASA 5500 Series, the prompt is ciscoasa>
This mode provides restricted view of the security appliance. You cannot configure anything from this mode. To get started with configuration, the first command you need to know is the enable command. Type enable and hit Enter. The initial password is empty, so hit Enter again to move on the next access mode (Privileged Mode).

ciscoasa> enable <– Unprivileged Mode
password: <– Enter a password here (initially its blank)
ciscoasa# <– Privileged Mode Privileged Mode:
Displays the # prompt. Enables you to change the current settings. Any unprivileged command also works in this mode. From this mode you can see the current configuration by using show running-config. Still, you cannot configure anything yet until you go to Configuration Mode. You access the Configuration Mode using the “configure terminal” command from the Privileged Mode. Configuration Mode:
This mode displays the (config)# prompt. Enables you to change all system configuration settings. Use exit from each mode to return to the previous mode.

ciscoasa> enable <– Unprivileged Mode
password: <– Enter a password here (initially its blank)
ciscoasa# configure terminal <– Privileged Mode
ciscoasa(config)# <– Configuration Mode
ciscoasa(config)# exit
ciscoasa# exit <– Back to Privileged Mode
ciscoasa> <– Back to Unprivileged Mode

The (config)# mode is sometimes called Global Configuration Mode. Some configuration commands from this mode enter a command-specific mode and the prompt changes accordingly. For example the interface command enters interface configuration mode as shown below:

ciscoasa(config)# interface GigabitEthernet0/1
ciscoasa(config-if)# <– Configure Interface specific parameters

The Unofficial Cisco ASA blog provides technical information and configuration examples about Cisco ASA 5500 Firewalls.

Most UNIX and Linux operating systems provide built-in time synchronisation functionality with its NTP (Network Time Protocol) daemon. If the NTP service is not available on your version of UNIXLinux, NTP version 4 is open source and can easily be downloaded and configured, compiled and installed from www.ntp.org.

Network Time Protocol is the standard service for time dissemination across TCP/IP networks. It provides accuracies of 1-50 milliseconds, depending on the characteristics of the synchronization source and network paths.

The configuration file fro the NTP daemon is named ntp.conf and contains a list of reference clocks that it can synchronise too. The command ‘server’ specifies the reference clock, any characters after the ‘#’ symbol are comments, example:
server time-a.nist.gov # Public NTP server: NIST
driftfile /var/lib/ntp/ntp.drift

The drift file command identifies the location where the drift is recorded (sometimes referred to as a ‘frequency error). This value can be offset by NTP to ensure of increased accuracy. When configured, NTP can be controlled using the commands ‘ntpd start’ ‘ntpd stop’ ‘ ntpq –p’ (displays status)

NTP can also authenticate timing resources Note: It is strongly recommends that you configure a time server with a hardware source rather than from the internet where there is no authentication. Authentication codes are specified in the ‘ntp.keys’ file.

Specialist NTP servers are available that can receive transmissions from either GPS or national time reference broadcasts. They are relatively cheap and the signal is authenticated providing a secure time reference.

Authentication allows passwords to be specified by the NTP server and its clients. NTP passwords or keys are stored in the ntp.keys file in the following format: number M (The M stands for MD5 encryption), password:

1 M mypassword

3 M my2ndpassword

5 M my3rdpassword

Authentication for NTP has been developed to prevent malicious tampering with system synchronisation just as firewalls have been developed to protect networks from attack but as with any system of security it only works if it is utilised.

Next we will see a simple Internet Access scenario which will help us understand the basic steps needed to setup an ASA 5510. Assume that we are assigned a static public IP address 100.100.100.1 from our ISP. Also, the internal LAN network belongs to subnet 192.168.10.0/24. Interface Ethernet0/0 will be connected on the outside (towards the ISP), and Ethernet0/1 will be connected to the Inside LAN switch.

The firewall will be configured to supply IP addresses dynamically (using DHCP) to the internal hosts. All outbound communication (from inside to outside) will be translated using Port Address Translation (PAT) on the outside public interface. Let’s see a snippet of the required configuration steps for this basic scenario:

Step1: Configure a privileged level password (enable password)
By default there is no password for accessing the ASA firewall, so the first step before doing anything else is to configure a privileged level password, which will be needed to allow subsequent access to the appliance. Configure this under Configuration Mode:

ASA5510(config)# enable password mysecretpassword

Step2: Configure the public outside interface
ASA5510(config)# interface Ethernet0/0
ASA5510(config-if)# nameif outside
ASA5510(config-if)# security-level 0
ASA5510(config-if)# ip address 100.100.100.1 255.255.255.252
ASA5510(config-if)# no shut

Step3: Configure the trusted internal interface
ASA5510(config)# interface Ethernet0/1
ASA5510(config-if)# nameif inside
ASA5510(config-if)# security-level 100
ASA5510(config-if)# ip address 192.168.10.1 255.255.255.0
ASA5510(config-if)# no shut

Step 4: Configure PAT on the outside interface
ASA5510(config)# global (outside) 1 interface
ASA5510(config)# nat (inside) 1 0.0.0.0 0.0.0.0

Step 5: Configure Default Route towards the ISP (assume default gateway is 100.100.100.2)
ASA5510(config)# route outside 0.0.0.0 0.0.0.0 100.100.100.2 1

Step 6: Configure the firewall to assign internal IP and DNS address to hosts using DHCP
ASA5510(config)# dhcpd dns 200.200.200.10
ASA5510(config)# dhcpd address 192.168.10.10-192.168.10.200 inside
ASA5510(config)# dhcpd enable inside

The above basic configuration is just the beginning for making the appliance operational. There are many more configuration features that you need to implement to increase the security of your network, such as Static and Dynamic NAT, Access Control Lists to control traffic flow, DMZ zones, VPN etc.

In this article I will explain the basic configuration steps needed to setup a Cisco 5505 ASA firewall for connecting a small network to the Internet. We assume that our ISP has assigned us a static public IP address (e.g 200.200.200.1 as an example) and that our internal network range is 192.168.1.0/24. We will use Port Address Translation (PAT) to translate our internal IP addresses to the public address of the outside interface. The difference of the 5505 model from the bigger ASA models is that it has an 8-port 10/100 switch which acts as Layer 2 only. That is, you can not configure the physical ports as Layer 3 ports, rather you have to create interface Vlans and assign the Layer 2 interfaces in each VLAN. By default, interface Ethernet0/0 is assigned to VLAN 2 and it’s the outside interface (the one which connects to the Internet), and the other 7 interfaces (Ethernet0/1 to 0/7) are assigned by default to VLAN 1 and are used for connecting to the internal network. Let’s see the basic configuration setup of the most important steps that you need to configure.

Step1: Configure the internal interface vlan
——————————————————
ASA5505(config)# interface Vlan 1
ASA5505(config-if)# nameif inside
ASA5505(config-if)# security-level 100
ASA5505(config-if)# ip address 192.168.1.1 255.255.255.0
ASA5505(config-if)# no shut

Step 2: Configure the external interface vlan (connected to Internet)
————————————————————————————-
ASA5505(config)# interface Vlan 2
ASA5505(config-if)# nameif outside
ASA5505(config-if)# security-level 0
ASA5505(config-if)# ip address 200.200.200.1 255.255.255.0
ASA5505(config-if)# no shut

Step 3: Assign Ethernet 0/0 to Vlan 2
————————————————-
ASA5505(config)# interface Ethernet0/0
ASA5505(config-if)# switchport access vlan 2
ASA5505(config-if)# no shut

Step 4: Enable the rest interfaces with no shut
————————————————–
ASA5505(config)# interface Ethernet0/1
ASA5505(config-if)# no shut
Do the same for Ethernet0/1 to 0/7.

Step 5: Configure PAT on the outside interface
—————————————————–
ASA5505(config)# global (outside) 1 interface
ASA5505(config)# nat (inside) 1 0.0.0.0 0.0.0.0

Step 6: Configure default route towards the ISP (assume default gateway is 200.200.200.2)
—————————————————————————————
ASA5505(config)# route outside 0.0.0.0 0.0.0.0 200.200.200.2 1

The above steps are the absolutely necessary steps you need to configure for making the appliance operational. Of course there are much more configuration details that you need to implement in order to enhance the security and functionality of your appliance, such as Access Control Lists, Static NAT, DHCP, DMZ zones, authentication etc.
Download the best configuration tutorial for any Cisco ASA 5500 Firewall model Here.