| TCP/IP Objectives |
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1. IP Addresses
2. Requirements for installing
TCP/IP protocol
3. DHCP
4. MPR and Multihomed
5. Methods and Modes of
Name Resolution
6. DNS
7. WINS
8. DHCP Relay Agent (DHCP Routing)
9.
RIP for Internet Protocol (IP Routing)
***Visit the Internetworking TCP/IP Notes site if you are studying for the TCP/IP exam***
The information below is not hardcore TCP/IP,
rather it is intended to present a foundation to build upon.
| IP Address |
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To install TCP/IP on a non-routed network you must specify the following:
To install TCP/IP on a routed network you must specify the following:
The Concept of Gateway
IP Address - an IP address is used to identify a node (any device that is attached to an internetwork. A node can also be referred to as a host) on the network and to specify routing information. Each node on the network must be assigned a unique IP address which is made up of the network ID plus a unique host ID. Example: 200.200.200.5
Subnet - a network in a multiple network environment that uses IP addresses derived from a single network ID
Subnet Mask ... an IP address consists of 4 octets and is usually displayed in the format 200.200.200.5, however this address on its own means very little because a subnet mask is required to show which part of the IP address is the Network ID (group of computers and devices located on the same physical network), and which part the Host ID (identifies a computer within a particular network).
Imagine the Network ID as the Street name, and Host ID as the House number, so with"1 Microsoft Way", "1" would be the Host ID, and "Microsoft Way" the Network ID. The subnet mask shows which part of the IP address is the Network ID, and which part is the Host ID. For example, with an address of 200.200.200.5, and a subnet mask of 255.255.255.0, the Network ID is 200.200.200, and the Host ID is 5.
| IP Address and DHCP |
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If there is a DHCP Server on your network,
you do not have to manually specify any of the above as a client. Your
distributor will do it for you.
DHCP CANNOT be used exclusively for name
resolution. DHCP is your distributor, not your manufacturer. DHCP can
When a client boots, it broadcasts a
message requesting data from a DHCP Server. The receiving DHCP server responds
with an IP address assignment for a specified period of time (called a lease
period). The client receives the data, integrates the data into its
configuration, and completes the boot process. Note: if no IP address is
available to lease to a client, the client cannot initialize TCP/IP.
When a lease expires, a DHCP Server can reassign the address to another computer. Client can extend its lease by indicating that it is still using the address. When 50% of the lease period is is reached, a client requests a lease extension -- if needed. If did not receive a lease extension at 50%, it requests an extension from the leasing DHCP server once 87.5 percent of its time period has expired. If at 87.5 the client did not successfully renew its lease, it broadcasts the extension request to all DHCP servers. If no server responds by the time the lease expires, all TCP/IP communications of that client will cease.
| Advanced IP Address (Multihomed) |
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Multiple IP Addresses on a Single NIC (Multihomed
computer)
Multiprotocol Router (MPR)
"... that is divided into two subnets
using the same cable segment." I -think- this means that there is only a
single NIC involved and MPR CANNOT be used on a single NIC.
Multihomed System
Enable PPTP filtering
Enable Security
| Name Resolution Overview |
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"A sad wind came, from invisible worlds ... / And she, she asked me about things unknowable / And I answered her with unattainable things."
OK, let's start by making a couple simple
ground rules: Numero Uno. The computer name is the
NetBIOS name. NetBIOS is specific to x86 Windows environments.
Host name is a Unix thing (yes, Windows NT can ALSO be set up
with a Host Name). Unix host names were born in Unix environments. The Internet
is primarily a Unix environment. "A Unix machine doesn't see the NetBIOS
name of your PC. It does see the host name."
The Application layer of TCP/IP:
| Socket based applications | NetBIOS Based Applications |
| Windows Sockets | NetBT (NetBIOS over TCP/IP) |
| TCP (transport layer) | TCP (transport layer) |
| IP (Internet layer) | IP (Internet layer) |
NetBT resolves NetBIOS names to IP addresses, which then resolve to NIC addresses via ARP cache or broadcast. NetBIOS (network basic input / output system) - is an application program interface (API) that can be used by application programs on a LAN. NetBIOS relies on a message format called Server Message Block (SMB) (Workstation Service installs the client for the SMB protocol). NetBIOS is used for browsing, interprocess communications between network servers, etc. Examples of NetBIOS applications include a Windows 95 machine sharing a directory, or a Windows NT Server sharing a printer, Network Neighborhood, Windows Explorer, blah, blah, blah. NWLink uses NetBIOS Over IPX (NBIPX) to resolve NetBIOS names into IPX addresses. No further resolution is required. NWLink caches NetBIOS names to perform the IPX address mappings. NWLink NetBIOS protocol is automatically installed when installing NWLink IPX/SPX Compatible Transport. NetBEUI protocol is an extension of NetBIOS and will NEVER pass through Windows Sockets.
For Windows Sockets applications, TCP/IP resolves host names to IP addresses, which then resolve to NIC addresses. Windows Sockets - is a Windows implementation of UC Berkley API. Berkley. Unix. Unix. Berkley.
Numero DOS. (no pun intended), As you can see, Name Resolution basically falls into two categories:
We're going explore WINS and DNS configuration GUI. Keep this in mind, If you are connecting your network to the Internet (you get a domain name, IP addresses, etc. from Internic) you'll want to use DNS. If you're not, you're using WINS.
Numero Tres. Just when it all seems to make perfect sense, you find out that you CAN use DNS (you'll see "enable DNS for Windows Resolution" below. It takes DNS name, shaves like 15 characters, and turns it into a NetBIOS name) and a HOSTS file (can be done if only using a HOSTS file) for NetBIOS name resolution. KEY POINT -- consider it an exception to the rule -- understand this, the bottom line function of both WINS and DNS is to resolve a physical computer's name (NetBIOS or and/or Host name) to an IP address (AKA, "I know who you are and where you are!")
On with the show ...
| Name Resolution Methods for NetBIOS Names |
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TCP/IP: Methods can be used to resolve NetBIOS computer names to IP addresses:
| Domain Name System (DNS) Name Resolution |
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DNS - Domain Name Server - "A server configured with the DNS daemon that maintains a database of IP addresses / host name mappings."
Name resolution - process of converting the host name to the IP address.
Once IP address determined, the physical address assigned
to the network adapter card can be resolved by ARP (Address Resolution
Protocol).
Host Name (by default, this is your computer name but it doesn't have to be) - is used to identify a computer when using a Domain Naming System (DNS) Server for name resolution AND to map computer names to IP addresses. The host name, combined with the domain name, comprise the fully qualified domain name (FQDN) for the computer, which the DNS server links to an IP address.
Domain Name is used in conjunction with the host name for name resolution by a Domain Naming System (DNS) server. It is used to map computer names to IP addresses. The host name, combined with the domain name, comprise the fully qualified domain name (FQDN) for the computer, which the DNS server links to an IP address. Example: In the FQDN 'host.globetrotting.com', 'host' is the host name, and 'globetrotting.com' is the domain name. The domain name contains a naming domain, created by the Internic, to identify the type of the organization, such as .edu for educational institution, .gov for government organization, or .com for commercial organization. DNS domain name DOES NOT = NT Server Domains.
DNS Service Search Order - specify DNS Server IP addresses that will provide name resolution.
DNS Suffix Search Order - specify DNS domain suffixes to append to hosts names during name resolution.
Before you can configure a DNS Server, you will need this information and it must be approved by Internic for use on the Internet; HOWEVER; if you are building the Server for internal use only, you can decide what names and IP addresses to use. You will need:
| WINS - Windows Internet Naming Service (AKA, NetBIOS Name Server) |
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WINS (Windows Internet Naming Service) Server (AKA, NetBIOS Name Server [NBNS]) - provides name resolution of NetBIOS computer names. WINS reduces NetBIOS background tracking by eliminating the NetBIOS broadcasts. A WINS client communicates directly with a WINS server to send a resource notification, release its NetBIOS name, or locate a resource.
Enable DNS for Windows Resolution - discussed above.
LMHOSTS - discussed above.
Once IP address determined, the physical address assigned
to the network adapter card can be resolved by ARP (Address Resolution
Protocol).
A NetBIOS name is:
| DHCP Routing |
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DHCP Routing: If your DHCP server is located across a router, you?ll need to install the DHCP Relay Agent Service on the router to forward DHCP broadcasts. A single DHCP Server can support multiple subnets connected by the NT Multi-Protocol Router (MPR ).
| IP Routing |
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What is Routing Information Protocol (RIP)?
Routing Information Protocol. A protocol used to exchange routing information with neighboring routers. You can use BOTH RIP for Internet Protocol and RIP for NWLink IPX/SPX compatible transport on the same network at the same time.
Routing and IP: RIP for Internet Protocol Service
NT can be a dynamic IP router or a static IP router or a
Routing Table
Built automatically by Windows NT based on IP configuration of your computer, routing tables control the routing decisions made by computers running TCP/IP.
Install RIP for NWLink IPX/SPX compatible
transport Service?
Service for Services
for Macintosh (as an AppleTalk Router)?