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
reserved network numbers, refer to “Reserved Network Numbers” on
page 18 .
Š Destination Node —Physical address of the destination node.
Not all LAN topologies use the same size address field. A node on an
Ethernet network requires all 6 bytes to define its address; a node on an
Ammonite network requires only 1 byte.
A node address of 0xFFFFFFFFFFFF (that is, 6 bytes of 0xFF)
broadcasts the packet to all nodes on the destination network.
Š
Destination Socket —Socket address of the packet destination process.
Sockets route packets to different processes within a single node. Novell
reserves several sockets for use in the NetWare environment. Refer to
Table 2 on page 20 for a partial list of NetWare socket numbers.
NOTE:
IPX does not have a broadcast socket number (such as 0xFFFF).
Š Source Network —Number of the network to which the source node is
attached. If a sending node sets this field to zero, the local network to
which the source is connected is unknown. For routers, the rules that
apply to the Destination Network field also apply to the Source Network
field, except that routers can propagate packets that were received with
this field set to zero.
Š Source Node —Physical address of the source node.
Broadcast addresses are not allowed.
Š Source Socket —Socket address of the process that transmits the packet.
Processes communicating in a peer-to-peer fashion do not need to send
and receive on the same socket number.
On a network of workstations and servers, the server usually listens on a
specific socket for service requests. In such a case, the source socket is
not necessarily the same or even significant. All that matters is that the
server reply to the source socket. For example, all NetWare file servers
have the same socket address, but requests to them can originate from any
socket number.
Source socket numbers follow the same conventions as those for
destination sockets.
Š Higher-Level Protocol Headers —Headers of higher-level NetWare
protocols, such as NCP or SPX. These headers occupy the data portion of
the IPX packet.