Information Technology Reference
In-Depth Information
The following is a list of distance vector routing protocols (including non-IP routing protocols):
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Routing Information Protocol (RIPv1 and RIPv2)
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Interior Gateway Routing Protocol (IGRP)
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Enhanced Interior Gateway Routing Protocol (EIGRP) (could be considered a hybrid)
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IPX Routing Information Protocol (IPX RIP)
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AppleTalk Routing Table Maintenance Protocol (RTMP)
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DEC DNA Phase IV
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Xerox's XNS Routing Information Protocol (XNS RIP)
Link-state routing protocols were developed to address some limitations of distance vector
protocols. When running a link-state routing protocol, routers originate information about
themselves (IP addresses), their connected links (number and type of links), and the state of
those links (up/down). The information is forwarded to all routers in the network. Each router
makes a copy of the information and does not change it. Each router independently calculates
the best paths to destinations and maintains a map of the network. Link-state routing protocols
are discussed in Chapter 8.
The following is a list of link-state routing protocols (including non-IP routing protocols):
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Open Shortest Path First (OSPF)
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Intermediate System-to-Intermediate System (IS-IS)
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IPX NetWare Link-Services Protocol (NLSP)
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DECnet Phase V
Hierarchical Versus Flat Routing Protocols
Some routing protocols require a network topology where some routers are assigned to a
backbone network. Routes from nonbackbone routers are fed into the backbone. Some of these
protocols support a two- or three-layer hierarchy. Some routers are assigned the role of
forwarding routes into the backbone. OSPF and IS-IS are examples of hierarchical routing
protocols.
Flat routing protocols do not require a hierarchical network topology, although they work a lot
better in a hierarchical network. Any router can be a peer of any other router in flat routing
protocols. No router is assigned a special role in the internetwork. RIP is an example of a flat
routing protocol.
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