Pop Quiz - Subnetting Challenge

Here are some subnetting questions to get the synapses firing on a Friday:

1. What range of addresses are encompassed by the summary address 10.45.128.0/18?

A) 10.45.128.0-10.45.128.255

B) 10.45.128.0-10.45.128.128

C) 10.45.128.0-10.45.191.255

D) 10.45.128.0-10.45.129.255

2. You need to configure a new branch office LAN with at least 812 usable IP addresses. The site desktop manager wants a single range of addresses to make it easier to configure the gateway and subnet mask on the computers and printers being deployed. Your company uses the 10.0.0.0/8 address space for internal networks and the subnet 10.128.0.0/16 has been reserved for new branch office LANs (WAN links are in a different subnet). Starting with the first available network in the reserved range, what is the most efficient subnet and CIDR mask for this new branch office?

A) 10.128.0.0/16

B) 10.128.0.0/23

C) 10.128.0.0/21

D) 10.128.0.0/22

3. The following access list is filtering traffic:

access-list 1 deny 192.168.64.0 0.0.31.255

access-list 1 permit any

Which of the following addresses will not be dropped? (select all that apply)

A) 192.168.64.1

B) 192.168.92.1

C) 192.168.96.1

D) 192.168.127.1

Answers after the break:

1. C) 10.45.128.0-10.45.191.255

2. D) 10.128.0.0/22

3. C & D) These addresses are not matched by this acl: 192.168.96.1 and 192.168.127.1