Q150577: ARP Request for Nonlocal Target Hosts on Same Physical Net
Article: Q150577
Product(s): Microsoft Windows NT
Version(s): 3.11 3.50 3.51
Operating System(s):
Keyword(s):
Last Modified: 09-AUG-2001
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The information in this article applies to:
- Microsoft Windows NT Workstation versions 3.5, 3.51
- Microsoft Windows NT Server versions 3.5, 3.51
- Microsoft TCP/IP-32 for Windows for Workgroups, versions 3.11, 3.11a, 3.11b
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SUMMARY
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If multiple logical subnets are present on the same physical network (with no
routers between the subnets), communication between hosts from different subnets
might not be possible. The packets destined for nonlocal subnets will be sent to
the router (if configured for one) or dropped (if no default gateway is
present). The Address Resolution Protocol (ARP) is used by the host to find the
physical address (MAC address) of a target host. An ARP request packet is
broadcast on the local subnet if the target host subnet address matches the
host's subnet address. If the subnet addresses do not match, then ARP resolves
the MAC addresses for the router.
MORE INFORMATION
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The following information is extracted from a Microsoft whitepaper on TCP/IP.
When running multiple logical subnets on the same physical network, the following
command can be used to tell IP to treat all subnets as local and to use ARP
directly for the destination:
route add 0.0.0.0 MASK 0.0.0.0 <my local ip address>
Thus, packets destined for "non-local" subnets will be transmitted directly onto
the local media instead of being sent to a router. In essence, the local
interface card can be designated as the default gateway. This might be useful
where several class "C" networks are being used on one physical network with no
router to the outside world.
Additional query words: prodnt
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Keywords :
Technology : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search kbAudDeveloper kbTCPIPSearch kbZNotKeyword3 kbTCPIP311 kbTCPIP311a kbTCPIP311b
Version : 3.11 3.50 3.51
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