Information Technology Reference
In-Depth Information
Briefly explain
feasibility condition
.
The feasibility condition (FC) is met when a neighbor's reported distance (RD) to a network is less
than the local router's feasible distance to the same destination network.
Briefly explain
reported distance
.
The reported distance or advertised distance is simply an EIGRP neighbor's feasible distance to the
same destination network. The reported distance is the metric that a router reports to a neighbor about
its own cost to that network.
Topology Table: Successor and Feasible Successor
The successor, feasible distance, and any feasible successors with their reported distances are kept by
a router in its EIGRP topology table or topology database. This table can be viewed using the
show ip
eigrp topology
command, as shown in Example 9-5.
Note:
The following table has been modified and does not completely relate to Packet Tracer Exercise 9-1.
Example 9-5
EIGRP Topology Table Command
Router#
show ip eigrp topology
IP-EIGRP Topology Table for AS 1
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
r - Reply status
<output omitted>
P 10.10.12.0/24, 1 successors, FD is 5514496
via 172.16.1.38 (5514496/28160), Serial0/1/0
via 172.16.1.42 (7693056/2172416), Serial0/1/1
<output omitted>
P 10.10.14.128/25, 1 successors, FD is 6026496
via 172.16.1.38 (6026496/2172416), Serial0/1/0
via 172.16.1.42 (7181056/28160), Serial0/1/1
<output omitted>
The topology table lists all successors and feasible successors that DUAL has calculated to destination
networks. Use the partial output in Example 9-5 to answer the following questions.
For route 10.10.12.0/24 . . .
What is the IP address of the successor?
172.16.1.38
What is the reported distance of the successor?
28160
What is the feasible distance of the successor?
5514496
What is the IP address of the feasible successor?
172.16.1.42
What is the reported distance of the feasible successor?
2172416
What is the feasible distance of the feasible successor?
7693056
