Table 10-4 Default Eigrp Configuration - Cisco ONS 15454 Software Feature And Configuration Manual

Configuring IP Routing
need not be acknowledged. Other types of packets (such as updates) require acknowledgment, which
is shown in the packet. The reliable transport has a provision to send multicast packets quickly when
there are unacknowledged packets pending. Doing so helps ensure that convergence time remains
low in the presence of varying speed links.
• The DUAL finite state machine embodies the decision process for all route computations. It tracks
all routes advertised by all neighbors. DUAL uses the distance information (known as a metric) to
select efficient, loop-free paths. DUAL selects routes to be inserted into a routing table based on
feasible successors. A successor is a neighboring router used for packet forwarding that has a
least-cost path to a destination that is guaranteed not to be part of a routing loop. When there are no
feasible successors, but there are neighbors advertising the destination, a recomputation must occur.
This is the process whereby a new successor is determined. The amount of time it takes to recompute
the route affects the convergence time. Recomputation is processor-intensive; it is advantageous to
avoid recomputation if it is not necessary. When a topology change occurs, DUAL tests for feasible
successors. If there are feasible successors, it uses any it finds to avoid unnecessary recomputation.
The protocol-dependent modules are responsible for network layer protocol-specific tasks. An
•
example is the IP EIGRP module, which is responsible for sending and receiving EIGRP packets
that are encapsulated in IP. It is also responsible for parsing EIGRP packets and informing DUAL
of the new information received. EIGRP asks DUAL to make routing decisions, but the results are
stored in the IP routing table. EIGRP is also responsible for redistributing routes learned by other
IP routing protocols.
Table 10-4

Table 10-4 Default EIGRP Configuration

Feature
Auto summary
Default-information
Default metric
Distance
EIGRP log-neighbor changes
IP authentication key-chain
IP authentication mode
IP bandwidth-percent
Cisco ONS 15454 SONET/SDH ML-Series Multilayer Ethernet Card Software Feature and Configuration Guide, R4.0
10-22
shows the default EIGRP configuration.
Default Setting
Enabled. Subprefixes are summarized to the classful network
boundary when crossing classful network boundaries.
Exterior routes are accepted and default information is passed
between IGRP or EIGRP processes when doing redistribution.
Only connected routes and interface static routes can be redistributed
without a default metric. The metric includes:
•
•
•
•
•
Internal distance: 90.
External distance: 170.
Disabled. No adjacency changes logged.
No authentication provided.
No authentication provided.
50 percent.
Chapter 10
Bandwidth: 0 or greater kbps.
Delay (tens of microseconds): 0 or any positive number that is a
multiple of 39.1 nanoseconds.
Reliability: Any number between 0 and 255 (255 means
100 percent reliability).
Loading: Effective bandwidth as a number between 0 and 255
(255 is 100 percent loading).
MTU: Maximum transmission unit size of the route in bytes. 0 or
any positive integer.
Configuring Networking Protocols
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