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*Keypoints:Know the 4 ways to reduce routing loops (listed above) and what they mean.Know there are 2 types of routing table entries 1) Permanent and 2) Temporary.Link State Concepts
The Link State Routing algorithm maintains a more complex table of topology information. Routers
using a link state routing protocol have a complete understanding and view of the entire network. The
Link State algorithm uses Link State Packets (LSP) to inform other routers of distant links. All routers
exchange LSP to build a total view of the network. OSPF is a Link State Routing Protocol.
When the topology changes, the first routers to find out sends LSP to all other routers on the internet-
work. All routers then re-calculate the best path to any affected route. Link State routing protocols are
more intensive in terms of power, memory, and bandwidth required.
Differences between Distance Vector and Link State
·
Distance Vector gets all its information second hand or gossip whereas link state routing ob-
tains a total topology of the internetwork.
·
Distance Vector determines the best path by counting hops. Links State uses a complex band-
width analysis.
·
Distance Vector updates topology changes every 30 seconds as default which causes a slow
convergence time. Link State can be triggered by topology changes resulting in faster conver-
gence times.
·
Link state is harder to setup.
Problems with Link State
Link-state (OSPF) needs lots of processing power to rebuild the routing database (tree). Network
bandwidth, is another problem. Link-state info can flood the network.
*Keypoints:Routers can learn hops dynamically by receiving periodic updates from other routers, or by defaultroutes.Know the differences between Distance Vector and Link State protocols.Routing Protocols
Routers can be used to segment networks by routing between two or more interfaces. Broadcasts will
be filtered and the packets will be routed based upon the destination network address (IP or IPX).
Routing protocols such as RIP, IGRP, OSPF, etc. are used to route information between routers. These
differ from Routed protocols such as TCP/IP, IPX, AppleTalk, etc.
Multiprotocol Routing
There are 2 types of multiprotocol routing:
Separate
A multiprotocol routing environment in which each protocol is not aware of the other protocols on the
same router. RIP and OSPF are separate routing protocols.
Integrated
A multiprotocol routing environment where each protocol is aware of the other protocols and they
share the results of the routing algorithm. EIGRP is an integrated routing protocol that integrates sup-
port for IP, AppleTalk and IPX using a distance vector algorithm based on IGRP.