202 Chapter 6: IP Routing
Foundation Summary
This section contains tables and lists that provide a convenient review of many key concepts in
this chapter. If you are already comfortable with the topics in this chapter, this summary could
help you recall a few details. If you have just read this chapter, this review should help solidify
some key facts. If you are doing your final preparation before the exam, Tables 6-5 and 6-6 are
a convenient way to review the day before the exam.
Here are some of the technical requirements that might be expected of a routing protocol:
·
Must adapt to change quickly and easily
·
Does not create a great deal of traffic
·
Scales to a large size
·
Is compatible with existing hosts and routers
·
Supports variable-length subnet masks and discontiguous subnets
·
Supports policy routing
·
Can be used between autonomous systems
·
Is based on industry standards
Routing protocols consume network, CPU, and memory resources. The amount of bandwidth
that is consumed depends on several issues:
·
How often will the route be updated?
·
How much of an update is being transmitted?
·
How many others will receive the update?
Table 6-5
Contrasting a RIP Protocol and an OSPF Protocol
Feature
RIP V1 (Distance-Vector
Protocol)
OSPF (Link-State Protocol)
Route learning
Learns about routes from its
neighbor. Information gained
is from one perspective.
Learns about routers based on the database of
information provided by every router in the area.
Every router in the area contains the same
information.
Acknowledging
updates
Does not acknowledge
updates.
Acknowledges updates.
Routing updates
Sends the entire routing table
at regular intervals.
Sends incremental routing updates and only
when changes occur in the network.
Addressing
Uses classful addressing.
Fixed-length subnet masks.
Uses classless addressing. Variable-length
subnet masks.
Route
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Uses broadcast addresses.
Uses multicast addresses.
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