Answer to Question #289935 in Computer Networks for Tran Huu Dang

Question

A company network composed of two LANs (Local Area Networks) respectively named LAN1 and LAN2. Each LAN is connected to an edge router (R1 and R2) and each edge router is connected to a central router (RC) via point-to-point links (PPL1 and PPL2). The central router is also connected to the Internet via the point-to-point link (PPLX)

1. Knowing the largest number of computer that connect a LAN is 60 (without the router). Which appropriate prefix length will you use ? Which smallest address bloc could your ISP provide you if it just receive the bloc 211.2.0.0/16 (assume all the address space of this bloc is available for the ISP customers and the first appropriate sub-bloc is for you)? 
2. Which address plan could you propose (sub-net address allocation)?

Answer 1

A company network composed of two LANs (Local Area Networks) respectively named LAN1 and LAN2. Each LAN is connected to an edge router (R1 and R2) and each edge router is connected to a central router (RC) via point-to-point links (PPL1 and PPL2). The central router is also connected to the Internet via the point-to-point link (PPLX)

1. Knowing the largest number of computer that connect a LAN is 60 (without the router). Which appropriate prefix length will you use ? Which smallest address bloc could your ISP provide you if it just receive the bloc 211.2.0.0/16 (assume all the address space of this bloc is available for the ISP customers and the first appropriate sub-bloc is for you)? 
2. Which address plan could you propose (sub-net address allocation)?

 

Answer:

Def:

LAN-Local Area Network is a collection of devices such as Switches,hub,router,bridge etc. connected together in one physical location such as building, office ,university.

The company can face some challenges of connecting two LANS directly.

The two routers can add a layer of complexity to the project instead use wireless bridge. Install wireless network adapted in the PC,themselves .

If central router fails the two Networks can’t function because of direct link that’s is point to point network.

If internet is disrupted the whole network will be plugged out because of sharing one connected internet.

1.Prefix length specifies the number of bits in the IP address that are to be used as the subnet mask. In this case the prefix length is 64 bit long . According to the question the smallest address bloc to be use is 1.128.0.0/16 this subnet mask(211.2.0.0/16) this address falls under class B of subnets because it’s a 16 bit.

2.The subnet address location which will  be preferred in this question  is 172.168.10.1.