Information Technology Reference
In-Depth Information
EIGRP for IPv4 Summary
The characteristics of EIGRP for IPv4 networks follow:
Hybrid routing protocol (a distance-vector protocol that has link-state protocol
characteristics).
■
Key
To p i c
Uses IP protocol number 88.
■
Classless protocol (supports VLSMs).
■
Default composite metric uses bandwidth and delay.
■
Yo u c a n f a c t o r l o a d a n d r e l i a b i l i t y i n t o t h e m e t r i c .
■
Sends partial route updates only when there are changes.
■
Supports MD5 authentication.
■
Uses DUAL for loop prevention.
■
Fast convergence.
■
By default, equal-cost load balancing with equal metrics. Unequal-cost load sharing
with the
variance
command.
■
Administrative distance is 90 for EIGRP internal routes, 170 for EIGRP external
routes, and 5 for EIGRP summary routes.
■
High scalability; used in large networks.
■
Multicasts updates to 224.0.0.10.
■
Does not require a hierarchical physical topology.
■
Provides routing for IPv4, plus legacy protocols such as AppleTalk and IPX.
■
EIGRP for IPv6 (EIGRPv6) Networks
Cisco has developed EIGRP support for IPv6 networks to route IPv6 prefixes. EIGRP for
IPv6 is configured and managed separately from EIGRP for IPv4; no network statements
are used. EIGRP for IPv6 retains all the same characteristics (network discovery, DUAL,
modules) and functions as EIGRP for IPv4. The major themes with EIGRP for IPv6 are as
follow s:
Implements the protocol-independent modules.
■
EIGRP neighbor discovery and recovery.
■
Reliable transport.
■
Implements the DUAL algorithm for a loop-free topology.
■
Same metrics as EIGRP for IPv4 networks.
■
Same timers as EIGRP for IPv4.
■
Uses same concepts of feasible successors and feasible distance as EIGRP for IPv4.
■
Uses the same packet types as EIGRP for IPv4.
■
