For the topology above, write the commands to do the followings:

1. Activate OSPF on Router B and advertise the needed networks

2. Write an access list (of your choice) to block PC with IP 192.168.20.2/24 from accessing networks 192.168.32.1/24 and 192.168.31.1/24, the code should show the location of the access list.

Sol82:

Assuming that the topology mentioned in the question is not provided, I cannot write the exact commands. However, here are the general commands that can be used to achieve the given tasks:

1. To activate OSPF on Router B and advertise the needed networks, the following commands can be used:

RouterB(config)# router ospf 1

RouterB(config-router)# network area

Here, refers to the network address that needs to be advertised, and refers to the wildcard mask associated with the network address. The area command specifies the OSPF area in which the network needs to be advertised.

1. To write an access list to block PC with IP 192.168.20.2/24 from accessing networks 192.168.32.1/24 and 192.168.31.1/24, the following commands can be used:

Router(config)# access-list deny ip host 192.168.20.2 192.168.32.0 0.0.0.255

Router(config)# access-list deny ip host 192.168.20.2 192.168.31.0 0.0.0.255

Router(config)# access-list permit ip any

Router(config)# interface

Router(config-if)# ip access-group in

Here, refers to the number assigned to the access list. The first two commands specify the networks that need to be blocked for the PC with IP address 192.168.20.2/24. The third command allows all other traffic. The interface command specifies the interface to which the access list needs to be applied, and the ip access-group in command applies the access list to inbound traffic on that interface.