Sunday, February 20, 2011

EIGRP

Enhanced Interior Gateway Routing Protocol - (EIGRP) is a Cisco proprietary routing protocol loosely based on their original IGRP. EIGRP is an advanced distance-vector routing protocol, with optimizations to minimize both the routing instability incurred after topology changes, as well as the use of bandwidth and processing power in the router. Routers that support EIGRP will automatically redistribute route information to IGRP neighbors by converting the 32 bit EIGRP metric to the 24 bit IGRP metric. Most of the routing optimizations are based on the Diffusing Update Algorithm (DUAL) work from SRI, which guarantees loop-free operation and provides a mechanism for fast convergence.

The data EIGRP collects is stored in three tables:
  • Neighbor Table: Stores data about the neighboring routers, i.e. those directly accessible through directly connected interfaces.
  • Topology Table: Confusingly named, this table does not store an overview of the complete network topology; rather, it effectively contains only the aggregation of the routing tables gathered from all directly connected neighbors. This table contains a list of destination networks in the EIGRP-routed network together with their respective metrics. Also for every destination, a successor and a feasible successor are identified and stored in the table if they exist. Every destination in the topology table can be marked either as "Passive", which is the state when the routing has stabilized and the router knows the route to the destination, or "Active" when the topology has changed and the router is in the process of (actively) updating its route to that destination.
Unlike most other distance vector protocols, EIGRP does not rely on periodic route dumps in order to maintain its topology table. Routing information is exchanged only upon the establishment of new neighbor adjacencies, after which only changes are sent. Also, it uses route tagging.

13 comments:

Ашот said...

nice!

AlekseyKO said...

I understand. Is very intersting!

Gregory said...

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SOLO KINOBI said...

thanks that is very interesting

travel2gether said...

oh. all this network stuff make's me cry.
Btw solo if you understand russian welcome to my blog. You can use google translate to understand me.

good luck!

D said...

cool!

D said...

Сool!

Dream said...

good)

Dei_Gratia said...

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werman said...

Epic

BumbaYay said...

That's cool man. I like it

Barry Kston said...

Good technology

mr_olbright said...

matan