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In case you're interested, here's some technical info on network protocols straight from the Microsoft Resource Kit.
The information below is not necessary to read! It is only provided for those who want to see what the resource kit offers, or for those that like to read techno-babble :-)
From the Win98 Resource Kit by Microsoft
Microsoft Transmission Control Protocol/Internet Protocol (TCP/IP) provides communication across interconnected networks that use diverse hardware architectures and various operating systems. TCP/IP can be used to communicate with computers running Windows 98, with devices using other Microsoft networking products, or with non-Microsoft systems such as UNIX.
Microsoft TCP/IP in Windows 98 extends the functionality that Microsoft TCP/IP offered in Windows 95. In Windows 95, Microsoft TCP/IP provided the following elements:
With Windows 98, the following enhancements are added:
Each workstation needs an IP address to communicate on a TCP/IP network such as the corporate network or the global public Internet. The section “Configuring IP Addresses” later in this chapter describes IP addresses in more detail, but for now it is just important to understand that there are two kinds of IP addresses, globally unique IP addresses and private IP addresses.
On the Internet, the Internet Assigned Numbers Authority (IANA) assigns groups of IP addresses to organizations. The organizations can then assign IP addresses within those groups to individual computers. This prevents multiple computers from having the same IP address.
For a computer to be visible on the Internet, it must be reachable through a globally unique IP address.
The IANA has reserved a certain number of IP addresses that will never be used on the global Internet. You can use these addresses for computers that will never be used to access the Internet.
In some cases, you can also use these addresses for computers that need partial connectivity to the Internet but do not need to be directly reachable from the Internet. For example, if you need only Web browsing and e-mail connectivity on a computer, that computer does not necessarily have to be directly reachable from the Internet.
However, in order to enable computers to use private IP addresses, you must deploy a firewall with proxy or Network Address Translator (NAT) capabilities. A proxy or NAT sits between a private network (a network of computers using private IP addresses) and the Internet. The firewall has a globally unique IP address that can be used on the Internet. When a computer on the private network sends a packet to the Internet, the NAT substitutes the source IP address on that packet for the NAT’s own IP address. Thus, the packets appear to originate from the NAT.
This configuration provides flexibility and a certain level of security: hosts on the Internet cannot directly send IP packets to the computer on the private network because they do not know and cannot use its IP address. The firewall can provide a level of administrative control for which machines and which applications can reach computers on the Internet, and vice versa.
For more information about private IP addresses, see Request for Comments (RFC) 1918. For more information about NATs, see RFC 1631.
Depending on your needs, you can use either private IP addresses or globally unique IP addresses for each workstation. You could also use both a private IP address and a globally unique IP address if you have a multihomed computer (a computer that has two different adapters, each connected to a different network). For example, a workstation could be connected both to the corporate network (using an adapter that is configured with a private IP address) and to the Internet (using a dial-up adapter that is configured with a globally unique IP address). For information about multihoming and this type of special configuration, see the section “Configuring Multihoming” later in this chapter.
Regardless of the type of IP address you choose, you have two options for configuring the IP addresses:
With dynamic IP addressing, the IP address can be configured automatically. This method is much simpler, decreases your management time, and enables you to reuse IP addresses. It is recommended for all sizes of networks.
In Windows 95, two types of dynamic IP addressing were available. For corporate networks, if there was a Dynamic Host Configuration Protocol (DHCP) server on the network, the computer could automatically obtain the IP address from the DHCP server. And for dial-up Internet connections, some Internet Service Providers (ISPs) automatically assigned your computer a dynamic IP address.
Windows 98 provides a third option, automatic private IP addressing. This option is recommended for simple networks that have one LAN (subnet) and no DHCP servers. With automatic private IP addressing, if no DHCP server is available, the computer automatically assigns itself a private IP address. (If a DHCP server later becomes available, the computer obtains an IP address from the DHCP server instead.) Computers using private IP addresses can communicate only with other computers using private IP addresses, on the same subnet. They are not directly reachable from the Internet.
With static IP addressing, you must manually configure the IP address.
Every computer on a TCP/IP network is identified by a unique 32-bit IP address, which also specifies routing information in an internetwork. An IP address looks like this:
This is referred to as dotted decimal notation, with each eight bits of an IP address (called an octet) separated from the next eight bits by a period. An IP address is a single value that contains two pieces of information:
Each host on the network uses the network ID and host ID to determine which packets it should receive or ignore, and to determine the scope of its transmissions (only hosts with the same network ID accept each other’s IP-level broadcasts).
The Internet community uses address classes to differentiate networks of various sizes. The network class can be determined from the first octet of its IP address. Table 15.1 summarizes the relationship between the first octet of an IP address and its network ID and host ID, using w.x.y.z. to designate the four octets of the IP address. As Table 15.1 shows, the value of the first octet determines which portion of the IP address will be the network ID and which portion will be the host ID.
For example, the first octet of the sample IP address 172.16.34.1 is 172. The w values portion of Table 15.1 shows that if the first octet has a value of 128-191, it is a Class B address. Thus, the sample IP address is a Class B address. Its first octet (172) is the network ID, and the remaining octets (16.34.1) are its host ID.
The sample IP addresses used in this chapter are private IP addresses, not IP addresses that are valid on the global Internet.
The table also identifies the total number of network IDs and host IDs for each address class that participates in the Internet addressing scheme.
Table 15.1 IP address classes
w values1, 2
|Available networks||Available hosts per net|
|1 Inclusive range for the first octet in the IP address.
1 The address 127 is reserved for loopback testing and interprocess communication on the local computer; it is not a valid network address. Addresses 224 and above are reserved for special protocols (IGMP multicasting and others), and cannot be used as host addresses.
Because the sender’s IP address is included in every outgoing IP packet, the receiving computer can derive the originating network ID and host ID from the IP address field. This is done by using subnet masks, which are 32-bit values that allow the recipient of IP packets to distinguish the network ID and host ID portions of the IP address.
The value of a subnet mask can also be represented in dotted decimal notation. Subnet masks are determined by assigning ones to bits that belong to the network ID and zeroes to bits that belong to the host ID. When the bits are in place, the 32-bit value is converted to dotted decimal notation, as shown in Table 15.2.
Table 15.2 Default subnet masks for standard IP address classes
|Address class||Bits for subnet mask||Subnet mask|
|Class A||11111111 00000000 00000000 00000000||255.0.0.0|
|Class B||11111111 11111111 00000000 00000000||255.255.0.0|
|Class C||11111111 11111111 11111111 00000000||255.255.255.0|
The result allows TCP/IP to determine the host ID and network ID of the local computer. For example, if the IP address is 172.16.34.1 and the subnet mask is 255.255.0.0, then the network ID is 172.16 and the host ID is 34.1.
Subnet masks are also used to further segment an assigned network ID among several local networks. For example, a network using the Class B network address 10.100 is one of over 16,000 Class B addresses capable of serving more than 65,000 nodes each. But if this corporate network includes 12 international LANs with 75 to 100 nodes each, it is better to use subnetting to make effective use of 10.100 than to apply for 11 more network IDs. In this case, the third octet of the IP address can be used as a subnet ID, using the subnet mask 255.255.255.0, which splits this Class B address into 254 subnets: 10.100.1 through 10.100.254, each of which can have 254 nodes. Any of these network addresses could be assigned to the 12 international LANs in this example. Within each LAN, each computer is assigned a unique host ID, and they all have the subnet mask 255.255.255.0.
All systems connected to the same local area network must have the same subnet mask.
Host IDs 0 and 255 should not be assigned to a computer; they are used as broadcast addresses that are typically recognized by all computers.
Windows 98 provides three methods of IP addressing:
Windows 98 provides the NetBIOS extended user interface (NetBEUI) protocol for compatibility with existing networks that use NetBEUI. Because NetBEUI is nonroutable and was designed for smaller LANs, you should use the TCP/IP or IPX/SPX-compatible protocol for enterprise-wide networks that require a routable protocol.
NetBEUI in Windows 98 provides two types of traffic:
NetBEUI in Windows 98 supports a NetBIOS programming interface that conforms to the IBM NetBEUI specifications and includes several performance enhancements. The NetBEUI module, Netbeui.vxd, is accessible through the NetBIOS interface.
If Windows 98 Setup detects NetBEUI during installation, it installs support for Microsoft NetBEUI automatically. If you are upgrading from a computer that did not have NetBEUI, Windows 98 does not automatically install it; however, you can add it at any time.
To install NetBEUI
The Advanced properties for NetBEUI affect only real-mode NetBEUI. These values are set dynamically for protected-mode NetBEUI.
To configure real-mode NetBEUI manually
If your computer has multiple network adapters, an instance of NetBEUI appears for each network adapter. You must configure each adapter with its own settings.
The Bindings tab shows which clients and services are currently using the NetBEUI protocol. For information about configuring bindings, see “Configuring Network Adapters” later in this chapter.
|Maximum Sessions||Used to identify the maximum number of connections to remote computers that can be supported from the redirector. This is equivalent to the sessions= parameter formerly specified in Protocol.ini.|
|NCBs (network control blocks)||Used to identify the maximum number of NetBIOS commands that can be used. This is equivalent to the ncbs= parameter formerly specified in Protocol.ini.|
The Microsoft Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) – compatible protocol (nwlink.vxd) supports the 32-bit Windows Sockets 1.1 programming interface, so that any Win32-based Windows Sockets 1.1 application can run on IPX/SPX with Windows 98. (There are no 16-bit Windows Sockets applications using IPX/SPX.)
The IPX/SPX-compatible protocol can be used by Client for NetWare Networks to communicate with NetWare servers or computers running File and Printer Sharing for NetWare Networks.
This protocol can also be used by Client for Microsoft Networks to communicate with computers running Windows for Workgroups 3.11 or Windows NT that are also running IPX/SPX.
The IPX/SPX-compatible protocol uses the nwnblink.vxd module to support computers that use NetBIOS over IPX and to support the NetBIOS programming interface. This protocol can also use NetWare servers configured as routers (and other IPX routers) to transfer packets across LANs.
The Microsoft IPX/SPX – compatible protocol is installed automatically when Client for NetWare Networks is installed. You can also install this protocol to support other network clients, including Client for Microsoft Networks.
To install the IPX/SPX-compatible protocol
When you install the IPX/SPX-compatible protocol, Windows 98 automatically detects and sets appropriate values for the frame type, network address, and other settings. However, in some cases you might need to configure settings for this protocol manually.
To configure the IPX/SPX-compatible protocol
If the computer has multiple network adapters, the list will contain an instance of the IPX/SPX-compatible protocol for each network adapter. You must configure each adapter with its own settings. You can only have four instances of IPX/SPX on your system, so if you have more than four adapters are installed, you should bind IPX/SPX only to the adapters that will use this protocol.
Table 15.10 IPX/SPX configuration values
|Force even-length IPX packets||Enabled only for Ethernet 802.3 on monolithic implementations that cannot handle odd-length packets.|
|Frame type1||Specifies the frame type based on detection. This value is used for network adapters that support multiple frame types. The possible
Ethernet 802.2 (default for NetWare 3.12 and later)
Token-ring Subnetwork Access Protocol (SNAP)
|Maximum connections||Specifies the maximum number of connections that IPX will allow. Configured dynamically.|
|Maximum sockets||Specifies the maximum number of IPX sockets that IPX assigns. Configured dynamically.|
|Network address||Specifies the IPX network address as a four-byte value. Configured dynamically.|
|Source routing2||Specifies the cache size to use with source routing. This parameter is used only on token-ring networks, where it is used to turn on
Important Cache size is specified by entry count, not byte count. The recommended value of 16 entries is the most efficient and best setting for most installations.
|1 Each time the computer starts, Windows 98 detects the frame type by sending a general RIP request in each
frame format. Based on the responses received from routers, Windows 98 determines the most prevalent frame type used and sets that as the default
2 Source routing is a method of routing data across bridges. For NetWare networks, this means forwarding NetWare frames across an IBM token-ring bridge. With NDIS protocols, source routing is done by the protocol. With ODI-based protocols, source routing is configured with the network adapter driver or using the NetWare route.com utility.
You should not need to change bindings in most circumstances. However, you can disable the bindings for a protocol if you do not want other computers using that protocol to see this computer. At least one protocol, however, must be bound to the network client for the computer to communicate with the network.
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