Q139983: Class C Subnetting Options for RAS Routing
Article: Q139983
Product(s): Microsoft Windows NT
Version(s): winnt:3.5,3.51,4.0
Operating System(s):
Keyword(s): kbnetwork
Last Modified: 08-AUG-2001
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The information in this article applies to:
- Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0
- Microsoft Windows NT Server versions 3.5, 3.51, 4.0
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SUMMARY
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Windows NT Remote Access Service (RAS) routing for LAN connectivity to an
Internet Provider requires an IP subnet address for the local LAN and a
different subnet addresses for the RAS link.
This article describes subnetting options with a class C address. A class "C"
address must be registered with the InterNIC. The InterNIC can be found at
http://rs.internic.net or by sending mail to Hostmaster@NIC.DDN.MIL . Your
Internet Service Provider may also supply you with a valid range of addresses.
MORE INFORMATION
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Following are 3 options to configure different subnet addresses for the RAS link
and local LAN:
Option 1
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Have the Internet Provider give you one address to use on your RAS link outside
of your class C addresses. This leaves you with the full 254 addresses for your
own use and no special subnetting. Many Internet Providers will not give you an
additional IP address. They may give you an entire additional class C range for
a fee.
Option 2
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Subnet mask of 255.255.255.192
This gives you 2 valid subnets with a maximum of 62 clients on the local LAN.
Subnet 1 would have the fourth octet of 64-127 (65-126 can be assigned). Subnet
2 would have the fourth octet of 128-191 (129-190 can be assigned). For example
XXX.XXX.XXX.65 would be the first address of subnet 1 and could be used for the
Windows NT network card and XXX.XXX.XXX.129 would be the first address of subnet
2 and could be used for the RAS connection.
Option 3 (unsupported)
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Subnet mask of 255.255.255.128.
This gives you 2 subnets with a maximum of 126 clients on the Local LAN. Both
subnets are technically invalid but work with Windows NT 3.5 and 3.51. Be sure
all clients on the network support this subnet mask. Microsoft cannot guarantee
this will work in future releases of Windows NT. Subnet 1 would have the fourth
octet of 0-127 (1-126 can be assigned). Subnet 2 would have the fourth octet of
128-255 (129-254 can be assigned). For example XXX.XXX.XXX.1 is the first
address of subnet 1 and could be used for the Windows NT network card and
XXX.XXX.XXX.129 is the first address of subnet 2 and could be used for the RAS
connection.
Additional query words: prodnt
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Keywords : kbnetwork
Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version : winnt:3.5,3.51,4.0
Issue type : kbhowto
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