Novell NETWARE 6, Руководство пользователя

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Internetwork Packet Exchange
Internetwork Packet Exchange
103-000176-001
August 29, 2001
Novell Confidential
Manual 99a
38
July 17, 2001
IPX network. After you configure a board and select a driver during the initial
router configuration, the router sends a RIP
all routes request packet to the
network. From the responses it receives, the router determines the network
number and frame type it needs to use.
Reserved Network Numbers
The destination network of an IPX packet is typically an IPX network to
which a unique network number has been assigned. However, three network
numbers—0x0, 0xFFFFFFFF, and 0xFFFFFFFE—are reserved and cannot be
used to identify a specific network. These numbers have the following
meanings:
Š 0x0 —Represents the local network segment. If a router receives a packet
whose destination network number is 0, the packet's source and
destination nodes are attached to the same segment.
Š 0xFFFFFFFF —Represents an all routes request between NetWare
routers. If a router receives a packet whose destination network number
is FFFFFFFF, it sends all the routes it knows about to the requesting
router.
Š 0xFFFFFFFE —Represents the default route . This is an advertised
destination to which IPX packets with unknown destination networks are
forwarded.
With NetWare routing software, a router that receives an IPX packet with an
unknown destination network can do one of two things: If another router on
the network is advertising 0xFFFFFFFE, the router forwards the packet to that
router. If 0xFFFFFFFE is not advertised on the network, the packet's
destination remains unknown and the router discards the packet.
Both RIP and NLSP have been modified to recognize 0xFFFFFFFE as the
default route. On a RIP network, the default route is typically advertised by a
RIP router that connects the LAN to a larger network infrastructure, such as a
corporate backbone or
transit LAN .
The routing software cannot advertise the default route dynamically, but you
can configure the router to advertise it
as a static route . To read about static
routes, refer to “Static Routes and Services.”