Difference between revisions of "Bjeff CCNP 1"
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==2.1 EIGRP Fundamentals and Features== | ==2.1 EIGRP Fundamentals and Features== | ||
| − | === Fast convergence === | + | ===Fast convergence=== |
| + | A router running EIGRP stores all its neighbors’ routing tables so that it can quickly adapt to alternate routes if a preferred route disappears. If an appropriate route does not exist, EIGRP queries its neighbors to discover an alternate route. These queries propagate until an alternate route is found. | ||
| − | === VLSM support === | + | ===VLSM support=== |
| + | EIGRP is a classless routing protocol, which means that it advertises a subnet mask for each destination network. Support for VLSM allows for different subnetmasks within the same network and support for non-contiguous subnetworks. EIGRP routes are automatically summarized at the major network number boundary. However, EIGRP can be configured to summarize on any bit boundary on any router interface. | ||
| − | === Partial updates === | + | ===Partial updates=== |
| + | EIGRP does not send periodic updates. Instead, it sends partial triggered updates. The updates are sent only when the path or the metric changes for a route, and they contain only information about the changed routes. Propagation of partial updates is automatically bounded so that only those routers that need the information are updated. Partial updates are handled by using multicast and unicast packets instead of broadcast packets. As a result, EIGRP consumes significantly less bandwidth than IGRP. This behavior is different than link-state protocols, in which an update is transmitted to all link-state routers within an area. | ||
| − | === Multiple network-layer protocol support === | + | ===Multiple network-layer protocol support=== |
| + | EIGRP supports IP, AppleTalk, and Novell NetWare IPX through the use of protocol-dependent modules. These modules are responsible for protocol requirements specific to the network layer. The rapid convergence and sophisticated metric structure of EIGRP offers superior performance and stability when implemented in IPX and AppleTalk networks. | ||
==2.2 EIGRP Components and Operation== | ==2.2 EIGRP Components and Operation== | ||
Revision as of 18:28, 9 February 2009
Contents
CCNP 1
2.1 EIGRP Fundamentals and Features
Fast convergence
A router running EIGRP stores all its neighbors’ routing tables so that it can quickly adapt to alternate routes if a preferred route disappears. If an appropriate route does not exist, EIGRP queries its neighbors to discover an alternate route. These queries propagate until an alternate route is found.
VLSM support
EIGRP is a classless routing protocol, which means that it advertises a subnet mask for each destination network. Support for VLSM allows for different subnetmasks within the same network and support for non-contiguous subnetworks. EIGRP routes are automatically summarized at the major network number boundary. However, EIGRP can be configured to summarize on any bit boundary on any router interface.
Partial updates
EIGRP does not send periodic updates. Instead, it sends partial triggered updates. The updates are sent only when the path or the metric changes for a route, and they contain only information about the changed routes. Propagation of partial updates is automatically bounded so that only those routers that need the information are updated. Partial updates are handled by using multicast and unicast packets instead of broadcast packets. As a result, EIGRP consumes significantly less bandwidth than IGRP. This behavior is different than link-state protocols, in which an update is transmitted to all link-state routers within an area.
Multiple network-layer protocol support
EIGRP supports IP, AppleTalk, and Novell NetWare IPX through the use of protocol-dependent modules. These modules are responsible for protocol requirements specific to the network layer. The rapid convergence and sophisticated metric structure of EIGRP offers superior performance and stability when implemented in IPX and AppleTalk networks.