CORRECT TEXT
A sporting goods manufacturer has decided to network three (3) locations to improve efficiency in
inventory control. The routers have been named to reflect the location: Boston, Frankfurt, and
Lancaster.
The necessary networking has been completed at each location, and the routers have been
configured with single area OSPF as the routing protocol. The Boston router was recently installed
but connectivity is not complete because of incomplete routing tables. Identify and correct any
problem you see in the configuration.
Note: The OSPF process must be configured to allow interfaces in specific subnets to participate in
the routing process.
Answer: See the explanation
Explanation:
The question mentioned Boston router was not configured correctly or incomplete so we should
check this router first. Click on Host B to access the command line interface (CLI) of Boston router.Boston>enable (type cisco as its password here) Boston#show running-config
First, remember that the current OSPF Process ID is 2 because we will need it for later configuration.
Next notice that in the second “network” command the network and wildcard mask are
192.168.155.0 and 0.0.0.3 which is equivalent to 192.168.155.0 255.255.255.252 in term of subnet
mask. Therefore this subnetwork’s range is from 192.168.155.0 to 192.168.155.3 but the ip address
of s0/0 interface of Boston router is 192.168.155.5 which don’t belong to this range -> this is the
reason why OSPF did not recognize s0 interface of Boston router as a part of area 0. So we need to
find a subnetwork that s0 interface belongs to.
IP address of S0 interface: 192.168.155.5/30 Subnet mask: /30 = 1111 1111.1111 1111.1111
1111.1111 1100 Increment: 4 Network address (which IP address of s0 interface belongs to):
192.168.155.4 (because 4 * 1 = 4 < 5) Therefore we must use this network instead of 192.168.155.0
network Boston#configure terminal Boston(config)#router ospf 2 Boston(config-router)#no network
192.168.155.0 0.0.0.3 area 0 Boston(config-router)#network 192.168.155.4 0.0.0.3 area 0
Boston(config-router)#end Boston#copy running-config startup-config Finally, you should issue a
ping command from Boston router to Lancaster router to make sure it works well. Boston#ping
192.168.43.1
