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Scalability Features of Routing Protocols
Scalability Features of Routing Protocols
everal times in this book, as we look at the different routing proto-
cols--OSPF, IGRP, EIGRP, and BGP--we will refer back to distance-vector
and link-state routing protocol differences. It is important to identify how
these protocols differ from one another.
As networks grow and administrators implement or use Cisco-powered
networks, OSPF might not be the most efficient or recommended protocol to
use. OSPF does have some advantages of IGRP, EIGRP, and BGP, including:
It is versatile.
It uses a very scalable routing algorithm.
It allows the use of a routing protocol that is compatible with non-
Cisco routers.
BGP will be discussed in Chapters 7 through 9.
Cisco provides two other proprietary solutions that allow better scaling
and convergence, which can be very critical issues. These are the
Gateway Routing Protocol (IGRP)
Enhanced IGRP (EIGRP)
. Network
growth imposes a great number of changes on the network environment and
takes into consideration the following factors:
The number of hops between end systems
The number of routes in the routing table
The different ways a route was learned
Route convergence
IGRP and EIGRP can be used to maintain a very stable routing environment,
which is absolutely crucial in larger networks.
As the effects of network growth start to manifest themselves, whether or
not your network's routers can meet the challenges faced in a larger scaled
network is completely up to the routing protocol the routers are running. If
you use a protocol that's limited by the number of hops it can traverse, the
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