Redistribution For An Eigrp Process; Metric Weights For Eigrp Routing; Mismatched K Values - Cisco ASR 9000 Series Configuration Manual

Redistribution for an EIGRP Process

Redistribution for an EIGRP Process
Routes from other protocols can be redistributed into EIGRP. A route policy can be configured along with
the redistribute command. A metric is required, configured either through the default-metric command or
under the route policy configured with the redistribute command to import routes into EIGRP.
A route policy allows the filtering of routes based on attributes such as the destination, origination protocol,
route type, route tag, and so on. When redistribution is configured under a VRF, EIGRP retrieves extended
communities attached to the route in the routing information base (RIB). The SoO is used to filter out routing
loops in the presence of MPSL VPN backdoor links.

Metric Weights for EIGRP Routing

EIGRP uses the minimum bandwidth on the path to a destination network and the total delay to compute
routing metrics. You can use the metric weights command to adjust the default behavior of EIGRP routing
and metric computations. For example, this adjustment allows you to tune system behavior to allow for satellite
transmission. EIGRP metric defaults have been carefully selected to provide optimal performance in most
networks.
By default, the EIGRP composite metric is a 32-bit quantity that is a sum of the segment delays and lowest
segment bandwidth (scaled and inverted) for a given route. For a network of homogeneous media, this metric
reduces to a hop count. For a network of mixed media (FDDI, Ethernet, and serial lines running from 9600
bits per second to T1 rates), the route with the lowest metric reflects the most desirable path to a destination.

Mismatched K Values

Mismatched K values (EIGRP metrics) can prevent neighbor relationships from being established and can
negatively impact network convergence. The following example explains this behavior between two EIGRP
peers (ROUTER-A and ROUTER-B).
The following error message is displayed in the console of ROUTER-B because the K values are mismatched:
RP/0/RSP0/CPU0:Mar 13 08:19:55:eigrp[163]:%ROUTING-EIGRP-5-NBRCHANGE:IP-EIGRP(0) 1:Neighbor
11.0.0.20 (GigabitEthernet0/6/0/0) is down: K-value mismatch
Two scenarios occur in which this error message can be displayed:
• The two routers are connected on the same link and configured to establish a neighbor relationship.
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However, each router is configured with different K values.
The following configuration is applied to ROUTER-A. The K values are changed with the metric
weights command. A value of 2 is entered for the k1 argument to adjust the bandwidth calculation. The
value of 1 is entered for the k3 argument to adjust the delay calculation.
hostname ROUTER-A!
interface GigabitEthernet0/6/0/0
ipv4 address 10.1.1.1 255.255.255.0
router eigrp 100
metric weights 0 2 0 1 0 0
interface GigabitEthernet0/6/0/0
The following configuration is applied to ROUTER-B. However, the metric weights command is not
applied and the default K values are used. The default K values are 1, 0, 1, 0, and 0.
hostname ROUTER-B!
Implementing EIGRP
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