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Enhanced Interior Gateway Routing Protocol
If a route from RIP, IGRP, or OSPF is injected into EIGRP, the route loses its
identity, and its metrics are converted from the original format to EIGRP's for-
mat. This can cause confusion within the router.
You can reset EIGRP metrics to help alleviate certain problems by using
the default-metric command, as follows:
default-metric bandwidth delay reliability load MTU
This command takes the metrics for the protocol being injected into EIGRP
and converts them directly to values that EIGRP can use. The bandwidth is
the capacity of the link. The delay is the time in microseconds, and reliability
and load are values from 1 to 255. The MTU is the maximum transmission
unit size in bytes.
Finally, you can change the distance values that are assigned to EIGRP (90
internal and 170 external). The distance value tells the router which protocol
to believe. The lower the distance value, the more believable the protocol.
The distance values for EIGRP are changed with the following command
from within the EIGRP session:
distance eigrp internal-distance external-distance
and external-distance have a range of values from
1 to 255.
Remember that a value of 255 tells the router to ignore the route. So
unless you want the routes from the protocol to be ignored, never use the
value 255.
Troubleshooting EIGRP
There are several commands that can be used on a router to aid in trouble-
shooting EIGRP. Table 6.5 contains all of the commands that are used in
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