Information Technology Reference
In-Depth Information
Managed and configured separately from EIGRP for IPv4.
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Requires a router ID before it can start running.
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Configured on interfaces. No network statements are used.
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The difference is the use of IPv6 prefixes and the use of IPv6 multicast group FF02::A for
EIGRP updates. Another difference is that EIGRP for IPv6 defaults to a shutdown state for
the routing protocols and must be manually or explicitly enabled on an interface to be-
come operational. Because EIGRP for IPv6 uses the same characteristics and functions as
EIGRP for IPv4 covered in the previous section on EIGRP, they are not repeated here.
EIGRP for IPv6 Design
Use EIGRP for IPv6 in large geographic IPv6 networks. EIGRP's diameter can scale up to
255 hops, but this network diameter is not recommended. EIGRP authentication can be
used instead of IPv6 authentication.
EIGRP for IPv6 can be used in the site-to-site WAN and IPsec VPNs. In the enterprise
campus, EIGRP can be used in data centers, server distribution, building distribution, and
the network core.
EIGRP's DUAL algorithm provides for fast convergence and routing loop prevention.
EIGRP does not broadcast its routing table periodically, so there is no large network over-
head. The only constraint is that EIGRP for IPv6 is restricted to Cisco routers.
EIGRP for IPv6 Summary
The characteristics of EIGRP for IPv6 are as follows:
Uses the same characteristics and functions as EIGRP for IPv4.
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Key
To p i c
Hybrid routing protocol (a distance-vector protocol that has link-state protocol
characteristics).
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Uses Next Header protocol 88.
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Routes IPv6 prefixes.
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Default composite metric uses bandwidth and delay.
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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 .
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Sends partial route updates only when there are changes.
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Supports EIGRP MD5 authentication.
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Uses DUAL for loop prevention and fast convergence.
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By default, equal-cost load balancing. Unequal-cost load balancing with the
variance
command.
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Administrative distance is 90 for EIGRP internal routes, 170 for EIGRP external
routes, and 5 for EIGRP summary routes.
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Uses IPv6 multicast FF02::A for EIGRP updates.
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High scalability; used in large networks.
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