Information Technology Reference
In-Depth Information
Parent and Child Routes
What is the main difference between a parent route and an ultimate route?
A parent route does not have a next-hop IP address or an exit interface. Although a parent route is a
level 1 route, the ultimate route is derived from a child route of the parent.
What is the relationship between parent and child routes?
A child route is a level 2 route that provides the next-hop IP address or exit interface for routing traf-
fic to the destination.
In the partial output of the routing table in Example 8-1, indicate whether each route is a parent route
or a child route by checking the appropriate column.
Example 8-1
Parent and Child Routes: Classful
10.0.0.0/30 is subnetted, 2 subnets
R 10.10.10.0 [120/1] via 10.10.10.5, 00:00:28, Serial0/0/0
C 10.10.10.4 is directly connected, Serial0/0/0
Route
Parent
Child
10.0.0.0
X
10.10.10.0
X
10.10.10.4
X
In Table 8-1, describe each part of the partial output shown in Example 8-1.
Table 8-1
Command Output Description
Command Output
Description
10.0.0.0
Classful network
/30
Subnet mask for child routes
is subnetted, 2 subnets
Parent route with two child routes
R
Route source is RIP
10.10.10.0
First child route
120
AD value for RIP routes
1
RIP metric, 1 hop
via 10.10.10.5
Next-hop IP address for this child route
00:00:28
Time since last update from neighbor
Serial0/0/0
Exit interface for first child route
C
Source is connected route
10.10.10.4
Second child route
Serial0/0/0
Exit interface for second child route
