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Subnetting

8 important questions on Subnetting

What is the subnetmask address you are going to use? Justify your answer.

255.255.255.240 - CIDR / 28

Assign the subnets of the network classes below

A

192.168.1.0/ 28

192.168.1.1 – 192.168.1.14

B

192.168.1.16/ 28

192.168.1.17 – 192.168.1.30

C

192.168.1.32/ 28

192.168.1.33 – 192.168.1.46

D

192.168.1.48/ 28

192.168.1.49 – 192.168.1.62

E

192.168.1.64/ 28

192.168.1.65 – 192.168.1.78

F

192.168.1.80/ 28

192.168.1.81 – 192.168.1.94

What is the 32-bit binary equivalent of the IP address 223.1.3.27? Justify your answer

11011111 . 00000001 . 00000011 . 00011011

Define and contrast the following terms: subnet , prefix , and BGP route

A subnet is a portion of a larger network. a subnet does not contain a router, its boundaries are defined by the router and host interfaces
A prefix is the network portion of a CIDR address. A prefix covers one or more subnets. it's written in the form of a.b.c.d/x
A prefix along with its attributes, like AS PATH and NEXT HOP, is a BGP route

Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 223.1.17/24. Also suppose that Subnet 1 is required to support at least 60 interfaces, Subnet 2 is to support at least 90 interfaces, and Subnet 3 is to support at least 12 interfaces. Provide three network addresses (of the form a.b.c.d/x) that satisfy these constraints.

223.1.17.0/25, 223.1.17.128/26, 223.1.17.192/28

Why do we use NAT and what does it do? Justify your answer

We use NAT to more efficiently use the full range of ip addresses available. It translates IP addresses in one network to a single IP address known by another network.

What is the future of NAT? Are there other options? Justify your answer

Uncertain at best, NAT routers often do not support IPv6 which is the future. IPv6 does not require NAT

Suppose you purchase a wireless router and connect it to your cable modem. Also suppose that your ISP dynamically assigns your connected device (that is, your wireless router) one IP address. Also suppose that you have five PC's at home that use 802.11 to wirelessly connect to your wireless router. How are IP addresses assigned to the five PCs? Does the wireless router use NAT? Why or why not

IP addresses are assigned to the PCs via DHCP on the wireless router
The wireless router uses NAT to translate network traffic from the single IP address known to the outside world, to the IP address at your home.