SYSTEM ADMINISTRATION
Chapter 6
Networking Protocols
TCP/IP (Transmission Control
Protocol/Internet Protocol)
• TCP/IP is a suite of protocols that allows nodes to
communicate with each other in a network
environment without regard to the type of machine
or operating system on that machine.
• The TCP/IP suite contains two core protocols, IP
and TCP.
• IP is a connectionless protocol used for transport at
the Network layer of the OSI Model.
• IP manages logical addressing and routing functions
for packet delivery.
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TCP/IP
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• The original developers of TCP/IP were the military
and academic institutions.
• Logical addressing in TCP/IP is necessary to route
packets between networks or inter-networks.
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TCP/IP
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• IP provides fragmentation services, packet timeout
services, and many options for transporting packets.
• The two most important fields in the IP header are the
source and destination address fields.
• An IP packet header and the data cannot exceed 65,535
bytes.
• When a nodes sends an IP packet, it compares the
destination address to its own address, determines the
network identifier, and either forwards the packet to the
router interface or attempt to deliver it on its own
segment.
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TCP/IP
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• Two protocols are used to support routing services: RIP
and OSPF.
• RIP is a distance vector routing protocol, meaning that
routing decisions are based only on the number of hops
in the path.
• OSPF is a link state protocol, meaning that routing
decisions are based on a number of criteria, including
hop count, congestion, speed of network, and other
criteria.
• Friendly names are supported for nodes running TCP/IP.
DNS supports friendly name to IP address resolution
services on the network.
IPX/SPX
• IPX/SPX is a Novell proprietary protocol used with
all versions of Novell’s NetWare products.
• IPX/SPX was designed to support a client-server
architecture, using remote procedure calls to
request service and respond with service. It can also
be used as a peer-to-peer network protocol.
• Like TCP/IP, IPX/SPX supports a suite of protocols:
IPX, SPX, and SAP.
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IPX/SPX
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• IPX is a connectionless protocol responsible for the
routing of packets, efficient delivery of datagrams,
and logical addressing.
• SPX is a connection-oriented protocol that manages
a session between nodes, including error control
and retransmission of missing or corrupt packets,
providing reliable delivery of data.
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IPX/SPX
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• SAP notifies the network when a service is
available. This is actually a broadcast, and when the
network is busy, SAP broadcasts can congest
bandwidth. It may be necessary to filter SAP
announcements at routers.
• NCP handles requests for services between the
client (workstation) and the server. It is a very
reliable service protocol, but can create large
amounts of traffic.
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IPX/SPX
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• To form a logical address when using IPX/SPX, the
administrator must add a network identifier in
hexadecimal format. The network identifier is 8 bits long.
• Once the network identifier is available, the node will
combine the network identifier and its own MAC address
to form a unique node address.
• IPX/SPX uses socket numbers to uniquely identify APIs
and client requests to those APIs. Often sockets are
assigned on the fly, but some socket numbers are
reserved by the NetWare operating system.
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IPX/SPX
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• Like TCP/IP, the two most important fields in the IPX
header are the source and destination node
addresses. IPX also includes individual fields for
source and destination network, and source and
destination socket.
• An IPX header will contain approximately 28 bytes
of information plus the payload.
• IPX routing employs two protocols: RIP for IPX and
NLSP.
Routing Protocols
• RIP is a distance vector protocol, making routing
decisions solely on the number of hops to the
destination network.
• NLSP is a link state protocol, more efficient, and
capable of making routing decisions on hop count
combined with bandwidth utilization, speed of
network, and other criteria.
Naming Conventions
• IPX/SPX does not require any specific naming
conventions for workstations (clients), but does
require that the servers have names that can use
alphanumeric characters, but cannot exceed 64
characters in length (old NetWare versions are
limited to 47 characters).
AppleTalk
• AppleTalk is the protocol of Macintosh computers,
originally designed for peer-to-peer networks.
• Although a later version of AppleTalk supports the
internetwork and routing, it remains best suited for
smaller networks.
• Logical addresses in AppleTalk are formed when the
node attaches to the network. It is an 8-bit or 16-bit
number, and will be stored and used again.
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AppleTalk
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• AppleTalk also uses network numbers to identify
segments.
• AppleTalk zones divide the network into logical
groupings for file sharing, printing and other
services.
• RTMP supports routing services.
• Nodes using AppleTalk will broadcast their friendly
name when attaching to the network. NBP will cache
the name, and supply this name to any node
requesting a service.
NetBEUI
• NetBEUI is an efficient, non-routable protocol useful
for small networks where Internet connectivity is not
needed.
• No configuration is needed for NetBEUI.
• All nodes using NetBEUI must have a name.
• NetBIOS supports friendly names for NetBEUI.
• No Network layer services are a part of the
NetBEUI/NetBIOS environment, so most often, they
are paired with other routable protocols such as
TCP/IP or IPX/SPX.
Interoperability
• TCP/IP is a versatile protocol that supports global
connectivity without regard to operating system.
• All major operating systems contain a TCP/IP
protocol stack, including Microsoft operating
systems, NetWare server versions 5.X and 6.X,
Linux, and UNIX.
• If an organization allows Internet connectivity for
users, the TCP/IP protocol must be implemented.
• IPX/SPX does not support access to Internet
resources, but is a robust network protocol.
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Interoperability
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• Many operating systems include support for
IPX/SPX.
• AppleTalk is native to only the Macintosh computer;
Microsoft includes AppleTalk-compatible services
with many of its operating systems.
• NetBEUI is native to the IBM LAN Manager and
Microsoft Windows products.
• Because NetBEUI is non-routable, it is only suitable
to very small peer networks.
• Macintosh has no provision for NetBEUI.