- KEY NAME: HKLM\System\CurrentControlSet\Services\Dfs
- Entry Name: PreferLogonDC
- Type: DWORD
- Value:1
NEVER CHANGE YOUR ORIGINALITY FOR OTHER’S BECAUSE, NO ONE CAN PLAY YOUR ROLE BETTER THEN YOU
Friday, January 30, 2015
How to Place Authenticating DC IN DFS Referral List
How to Strict AD Replication To A Specific Port
Method 2:-
- KEY NAME: HEKY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTDS\Parameters
- Entry Name: TCP/IP Port
- Value: Port No...
- KEY NAME:
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters
- Entry Name: DCTcpipPort
- Value: Port No...
How to Change Default DNS Interval For Domain Controllers
- KEY Name: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters
- Entry Name: DnsRefreshInterval
- Type: REG_DWORD
- Value: value in seconds
How to Check DCs Register Records with DNS Dynamically
- KEY Name: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters
- Entry Name: UseDynamicDns
- Type: REG_DWORD
- Value: 0(disabled) 1(enabled)
How to Netlogon Service on Domain Controller
- Service performs the registration of SRV records, CNAME and other DC records in the DNS Server to advertise the availability of Domain Controllers in the domain.
- SRV Records registered by NetLogon Service are stored in C:\Windows\System32\Config\NetLogon.DNS File.
- Performs registration of SRV Records every 24 hours depending on the version of Operating System in use.
- Registers the SRV Records for a site where there is no Domain Controller. This is called Site Coverege.
How to Prevent Registration of A and GC For Domains Controllers
- DomainName.Com A IP_Address
- gc._msdcs.DomainName.Com A IP_Address
- KEY Name: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetLogon\Parameters
- Entry Name: RegisterDnsARecords
- Data: DWORD
- Value: 1 (Register A Records), 0 (Do not register A Records)
Note: This regsitry entry does not exist by default.
How to Prevent Net Logon Service From Registering SRV & Domain Records
To disable this behaviour, use the below registry hack:
- KEY Name:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetLogon\Parameters
- Entry Name: UseDynamicDns
- Data: REG_DWORD
- Value: 0 (disabled registration of SRV
records dynamically) 1 (enabled registration of SRV records
dynamically)
Note: The default value is 1. So NetLogon performs the registration of SRV and other records dynamically. If you disable this then you must register the SRV and other Records found in C:\Windows\System32\Config\NetLogon.DNS file.
How to Change KCC Interval
- KEY Name: HKLM\System\CurrentControlSet\Services\NTDS\Parameters
- Entry Name: Repl topology update period (secs)
- Type: REG_DWORD
- Value: 0x384 (this is the default value)
ROSP AND FGPP
ADMT Migration & Networks Ports For Windows
- 389 - LDAP
- 88 - Kerberos
- 53 - DNS
- 445 - SMB/CIFS
- 3268 - GC
- 135 - RPC
- 1024-65535 - Dynamic Port Range
Saturday, January 10, 2015
layer model for osi
- Application
- Presentation
- Session
- Transport
- Network
- Data link
- Physical
- Definitions of hardware specifications
- Encoding and signaling
- Data transmission and reception
- Topology and physical network design
Definitions of hardware specifications
Encoding and signaling
Data transmission and reception
preventing Network Pocket Collisions
Monday, July 28, 2008
Networking Essentials
Network Orientation:
Peer to Peer Networks
- No dedicated server or hierarchy, also called a workgroup.
- Usually 10 or fewer workstations.
- Users act as their own administrator and security.
- Computers are in same general area.
- Limited growth.
Server Based Networks
- 10 or more users.
- Employs specialized servers.
- File and Print
- Application
- Fax
- Communications (gateways)
- Central administration.
- Greater security.
- Centralized backup.
- Data Redundancy.
- Supports many users
Combination Networks
- Combines the features of both Peer to Peer and Server based networks
- Users can share resources among themselves as well as access server-based resources.
| Network Topologies |
There are 4 basic topologies with variations
Bus Topology
- Bus consists of a single linear cable called a trunk.
- Data is sent to all computers on the trunk. Each computer examines EVERY packet on the wire to determine who the packet is for and accepts only messages addressed to them.
- Bus is a passive topology.
- Performance degrades as more computers are added to the bus.
- Signal bounce is eliminated by a terminator at each end of the bus.
- Barrel connectors can be used to lengthen cable.
- Repeaters can be used to regenerate signals.
- Usually uses Thinnet or Thicknet
- both of these require 50 ohm terminator
- good for a temporary, small (fewer than 10 people) network
- But its difficult to isolate malfunctions and if the backbone goes down, the entire network goes down.
Star Topology
- Computers are connected by cable segments to a centralized hub.
- Signal travels through the hub to all other computers.
- Requires more cable.
- If hub goes down, entire network goes down.
- If a computer goes down, the network functions normally.
- most scalable and reconfigurable of all topologies
Ring Topology
- Computers are connected on a single circle of cable.
- usually seen in a Token Ring or FDDI (fiber optic) network
- Each computer acts as a repeater and keeps the signal strong => no need for repeaters on a ring topology
- No termination required => because its a ring
- Token passing is used in Token Ring networks. The token is passed from one computer to the next, only the computer with the token can transmit. The receiving computer strips the data from the token and sends the token back to the sending computer with an acknowledgment. After verification, the token is regenerated.
- relatively easy to install, requiring ;minimal hardware
Mesh
- The mesh topology connects each computer on the network to the others
- Meshes use a significantly larger amount of network cabling than do the other network topologies, which makes it more expensive.
- The mesh topology is highly fault tolerant.
- Every computer has multiple possible connection paths to the other com-puters on the network, so a single cable break will not stop network communications between any two computers.
Star Bus Topology
- Several star topologies linked with a linear bus.
- No single computer can take the whole network down. If a single hub fails, only the computers and hubs connected to that hub are affected.
Star Ring Topology
- Also known as star wired ring because the hub itself is wired as a ring. This means it's a physical star, but a logical ring.
- This topology is popular for Token Ring networks because it is easier to implement than a physical ring, but it still provides the token passing capabilities of a physical ring inside the hub.
- Just like in the ring topology, computers are given equal access to the network media through
- the passing of the token.
- A single computer failure cannot stop the entire network, but if the hub fails, the ring that the hub controls also fails.
Hybrid Mesh
- most important aspect is that a mesh is fault tolerant
- a true mesh is expensive because of all the wire needed
- another option is to mesh only the servers that contain information that everyone has to get to. This way the servers (not all the workstations) have fault tolerance at the cabling level.
CCNA Number System
Introduction
A number system defines a set of values used to represent quantity. You may regard each digit as a box that can hold a number. In the binary system, there can be only two choices for this number -- either a "0" or a "1". In the octal system, there can be eight possibilities:
"0", "1", "2", "3", "4", "5", "6", "7".
In the decimal system, there are ten different numbers that can enter the digit box:
"0", "1", "2", "3", "4", "5", "6", "7", "8", "9".
In the hexadecimal system, we allow 16 numbers:
"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "A", "B", "C", "D", "E", and "F".
As demonstrated by the following table, there is a direct correspondence between the binary system and the Hexa system, with four binary digits translate directly into one hexadecimal digit. In computer usage, hexadecimal notation is especially common because it easily replaces the binary notation, which is too long and human mistakes in transcribing the binary numbers are too easily made.
BIN HEX DEC
----------------
0000 0 0
0001 1 1
0010 2 2
0011 3 3
0100 4 4
0101 5 5
0110 6 6
0111 7 7
----------------
1000 8 8
1001 9 9
1010 A 10
1011 B 11
1100 C 12
1101 D 13
1110 E 14
1111 F 15
Convert From Any Base To Decimal
Let's think more carefully what a decimal number means. For example, 1234 means that there are four boxes (digits); and there are 4 one's in the right-most box (least significant digit), 3 ten's in the next box, 2 hundred's in the next box, and finally 1 thousand's in the left-most box (most significant digit). The total is 1234:
Thus, each digit has a value: 10^0=1 for the least significant digit, increasing to 10^1=10, 10^2=100, 10^3=1000, and so forth.
Likewise, the least significant digit in a hexadecimal number has a value of 16^0=1 for the least significant digit, increasing to 16^1=16 for the next digit, 16^2=256 for the next, 16^3=4096 for the next, and so forth. Thus, 1234 means that there are four boxes (digits); and there are 4 one's in the right-most box (least significant digit), 3 sixteen's in the next box, 2 256's in the next, and 1 4096's in the left-most box (most significant digit). The total is:
Example. Convert the hexadecimal number 4B3 to decimal notation.
Solution: Original Number : 4 B 3
| | |
How Many Tokens : 4 11 3
Digit/Token Value: 256 16 1
Value: 1024 +176 + 3 = 1203
Another way is to think of a cash register with different slots, each holding bills of a different denomination
Convert From Decimal to Any Base
Again, let's think about what you do to obtain each digit. As an example, let's start with a decimal number 1234 and convert it to decimal notation. To extract the last digit, you move the decimal point left by one digit, which means that you divide the given number by its base 10.
The remainder of 4 is the last digit. To extract the next last digit, you again move the decimal point left by one digit and see what drops out.
The remainder of 3 is the next last digit. You repeat this process until there is nothing left. Then you stop. In summary, you do the following:
Now, let's try a nontrivial example. Let's express a decimal number 1341 in binary notation. Note that the desired base is 2, so we repeatedly divide the given decimal number by 2.
Let's express the same decimal number 1341 in hexadecimal notation.
Example. Convert the decimal number 3315 to hexadecimal notation.
Solution:
Note that from the Base Conversion Table, you can easily get the binary notation from the hexadecimal number by grouping four binary digits per hexadecimal digit, or from or the octal number by grouping three binary digits per octal digit, and vice versa.
Note: In 640-801 exam there is one question to convert a number from one base to others.
