Microsoft DNS, WINS and Networking

Check DNS DC entries
You may have to verify that DCs are properly registered in DNS and setup with SRV ()service records) found this useful link...

Check DC DNS entries


Central Ops
This WWW resource will help with debugging and information gathering for Organizations DNS and registered networks....it's a must have util!!!

CentralOps

NSLookup

As you move through cross platform environments the options and capabilities may vary.
Here is Microsoft's NSLookup.exe (MS ver) technet page.

Remote Desktop & Terminal Services
So a Web/App developer reboots a server and puts a call in saying they cannot RDP to the server but the SQL database is running...everyone else tells me the server is down....
I checked via the CLI and Powershell what was running and Terminal Services was running.

Off to the server room, thankfully the server was labelled, logged in and checked that RDP was enabled, the firewall was off, no IPSec configured....stop the bus... two network configs and one disabled. Time to check the Terminal Services config...Check TS NIC Config had to reboot the server after I changed the config to the NIC that is live. It was configured to pick whatever NIC...so hey ho...

More RDP URLs

WS2008 TS & Admin
WS2003 TS Tools

IP Addressing

An IP address is a numerical identifier that is configured in software (the Operating System).
It IDs NETWORKS and DEVICES on the network.
It designates the physical location of IDd  NETWORKS and DEVICES on the network, and is designed to allow communication between NETWORKS and DEVICES on the network, regard less of the type of LAN or Host.

(Hardware Address = MAC = Media Access Control Number is hard coded in to the Network Interface Card. It is used on the LAN to locate hosts on the local network.)

An IP Address = 32 bits of information = split 4 ways = 4 octests of 8 bytes
An IP Address depicted =Decimal,Binary or Hex 

Decimal = xxx.xxx.xxx.xxx so 192.168.0.10
Binary =xxxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx so10111111.00011111.00001010.11110000 
Hexidecimal = ac.10.1e.38 (checkout the windows registry to see IPs in Hex)

All of the above is HIERARCHICAL to provide Structure.....Network<->Subnet<->Host similar to telephone numbers have International-Area-local-telephone. Numbers are split!

The Split

Network Address = Used to define network Classes

Subnet/Host Address = Used to define subnets and hosts that are on the subnet

Network Address = Used to define network Classes
There are 5 network classes A B C D E

Class A

In the first octet of the address, the first bit is OFF or Disabled =0 this leaves a remaining 7 bits for network addressing.

bit pattern in the first octect = 01111111 (It's been designed that way!)

so 2 to power of 7 = 128 networks, ranged from 0-127
the usable range is 0-126 because 127.0.0.1 is a computer's local loopback and this address is therefore a diagnostic reservation for testing NICs.

Class A IP Address looks like 

Network.Host.Host.Host
0-126.0-255.0-255.0-255 (there are restrictions, but for now these numbers will do to get the idea)

Since you have 3 octets left for addressing hosts, thats 24bits = 2 to the power 24 = 16,77,216. I've said there are restrictions so always substract 2 from the hosts total value, just as a general rule. 

Class B IP Address Looks like

Network.Network.Host.Host
128->191.0-255.0-255.0-255

First byte or octet starts with the first and second bits set to 10xxxxxx (It's been designed that way!)

128 = 10000000
191 = 10111111

Leaves 2 to the power 16 -2 for reserved addresses = 65534 hosts and
16384 networks.  Keep in mind we have ;lost 2 bits from the network Octets so the total networks is 2 to the power of14 and not 16!

Class C IP Address Looks like

Network.Network.Network.Host
192-223.Network.Network.Host

192 = 11000000
223 = 11011111

First byte or octet starts with the first three bits set to 110xxxxx (It's been designed that way!)

Now we have 24 bits used for networks, 3 bits are reserved so 2 to the power of 21 = 2,097,152 networks and 2 to the power of 8 for hosts minus the two restricted reservations = 254 hosts

Restrictions....all host bytes with a pattern of all 0 or all 1 are not allowed, also on any subnet you will need an IP for a router/switch so in reality you will lose 3 addresses.

Private IP Addressing 
used on private networks.
Not routable over the internet.
Provide security and save address space.

Network Address Translation (NAT) is used to convert Private IP Addresses for use on external internet and Private IP Addresses are therefore hidden via NAT on the big bad WWW. Internet Service Providers provide public IPs for internet usage.

Class Private IP address Ranges

Class A 10.0.0.0->10.255.255.255
Class B 172.16.0.0 ->172.31.255.255
Class C 192.168.0.0->192.168.255.255
Class D 224-239 Multicast network
Class E 240-255 Reserved for scientists


Class C 192.168.0.0->192.168.255.255 is used in your house! Do not forget this....your router is a DHCP server that provides these address ranges and these are converted by NAT the same as for any business by your ISP.

If you do not have a DHCP router, a network in the house can still be used the computers will use the Automatic Private IP Addressing (APIPA) this address range

APIPA = 169.254.0.1->169.254.255.254

Subnetting

We can split Network addressesin to several network addresses....for some good reasons too...reduce network traffic, optimize network performance,simplified management, span large distances.

With Subnetting bits of the host address are reserved and used to define the network address, means fewer host addressses. Now we are heading in to the realms of Classless Internet Domain Routing (CIDR)

Recipe for a Solid Design (according to my Netwok+ nmanual)

• Determine amount of Network IDs- One for each Subnet and One for each Wide Area Network connection
• Determine amount of host IDs- Individual hosts and one for each router interface
• Base on Network and Host IDs-One Subnet for your entire Network, unique subnet ID for individual physical network segments, range of Host IDs oersubnet

Subnet Mask
 Without this all the above wont work. Subnet Masks are assigned so that network devices, anything using TCP/IP, can determine Network Addresses and Host Addresses. It is a 32 bit value and basically filters or masks Network Addresses and Host Addresses by representing bit positions for Network Addresses and Host Addresses.

Created by Network Admins, consists of 1s and 0s it is the 1s in the octets that determine the Network Addresses or bit positions.

Class A 10.0.0.0->10.255.255.255 Subnet Mask 255.0.0.0
Class B 172.16.0.0 ->172.31.255.255 Subnet Mask 255.255.0.0
Class C 192.168.0.0->192.168.255.255 Subnet Mask 255.255.255.0
                                                                   All default subnet masks

Classless Internet Domain Routing (CIDR)

ISPs use Classless Internet Domain Routing (CIDR) for enterprise or home IP Address assignment. They provide IP Addresses in slash notation. So for an example...192.168.10.32/28 this means your subnet mask is 

11111111.11111111.11111111.11110000       Manual numbering system conversions
255           . 255        . 255          . 240

you have to count all the 1s to figure out the subnet mask then convert to decimal.
We can also see we have 2 to the power 4 as total for host addresses which is 16 minus 2 for restricted address.
There are 32bits, 2 of which have to be kept for hosts, so the largest subnet can only be /30

Check this....Classless_Inter-Domain_Routing

Quick note....

/8->/15 =A
/16->/23=A&B
/24->/30=A&B&C

You get subnet calculators too if you fancy the easy way

Understanding TCP/IP addressing and subnetting basics

IPv6 Intro

Subnet Calculator

http://www.subnet-calculator.com/

Windows DHCP

Good forum info for ADs that have multiple dhcp servers...just experiencing this for the first time myself...anyway good read.

Multi-dhcp servers

DNS support for AD Tech-ref

Please Do Not Throw Sausage Pizza Away!!  The New OSI model

Started reading the Comptia Network+ study guide that I downloaded to my kindle.
I've always struggled remembering the Open Systems Interconnection Reference Model and it's layers...there is a surprise eh?

the layers are

1. Physical = Please
2. Data Link = Do
3. Network = Not
4. Transport = Throw
5. Session = Sausage
6. Presentation = Pizza
7. Application = Away

Thought I would write this up as it is a good way of remembering the layers!

If you are interested in the Comptia Network+ book (kindle edition)

If you are interested in the OSI Reference Model (Wikipedia) and a HowStuffWorks version

What is HTTP?

The very thing that lets me post and read my blog....but here is a definition from Wikipedia...Hypertext Transfer Protocol

Microsoft Remote Assistance
Uses TEREDO to map ip addr over the WWW so you may have to check your router and network settings..  what is....????   definition of TEREDO

From a command prompt type

netsh interface teredo show state

MSRA step by step guide to help you connect and provide remote assistance or support

MSRA from the command line interface you can also type

msra /? 

from a cmd shell..check if you have to run the cmd shell as admin though


Disconnect bell wire for better ADSL

Wi-Fi and Alternative Network Mediums and Hardware

IEEE802.org

www.wi-fi.org

Home PNA

Homeplug Alliance

Universal Powerline Association

Link Layer Topology Discovery (LLTD) Protocol

LLTD Wikipedia Definition

Tech Republic - What do the new Windows networking protocols do?

Create a Network Map in Windows 7

Link Layer Topology Discovery (LLTD) Responder (KB922120)

Disabling LLTD

Running the Link Layer Topology Discovery (LLTD) responder update for Windows XP on Windows Server 2003

Win7 Net Diags

New Network Diagnostic Framework and Network Tracing Features in Windows 7

Microsoft Message Analyzer-Replaces Network Monitor Message Analyzer enables you to capture, display, and analyze protocol messaging traffic; and to trace and assess system events and other messages from Windows components.

Network Analyzer Blog

How to reset TCP/IP by using the NetShell utility

Performance Enhancements in the Next Generation TCP/IP Stack--The Cable Guy

DSL Reports FAQ Tweaks

The Cable Guy: Network Diagnostics & Tracing in Windows

TechNet Magazine: The Cable Guy

General Net & WWW Utils

DNS Stuff

Unwanted wake-up events may occur when you enable the Wake On LAN feature in Windows 7 or in Windows Vista  a MAGIC PACKET????

IPv4 & IPv6

Microsoft--TCP/IP v4 and v6 

How to use automatic TCP/IP addressing without a DHCP server Automatic Private IP Addressing