ITNE3006 Design Network Infrastructure Assignment Answer

Answer :

ITNE3006 Design Network Infrastructure Assignment

PART 1

1. We compare both cisco enterprise composite network model and hierarchical network model. Based on their provided features, we select the cisco enterprise composite network model to create network design of VIT.

The hierarchical network works on layered architecture. It has three layers namely core, distribution and access layer. The primary or main connectivity device that is the entry point for the entire network, is placed at the core layer. ISP routers, edge routers, manageable switches are placed in this layer. This layer connects second layer, distribution layer. Several routers can be placed at this layer. This layer is responsible for access control, security policies and primarily create a boundary between core and access layer to separate access layer devices. Access layer handles all the types of end user connecting devices such as switch, hub, access points etc. and provide end user connectivity in both wired or wireless networks. This model provides modularity in design, resiliency, easy manageable network hierarchy and flexibility in the network. A sample network design to elaborate this concept is presented here.

The enterprise composite network model separates the entire large network in to smaller functional networks that are called as modules. Modules are further creating a small hierarchical network that connect the end user connecting devices. These modules provide flexibility in design and made the implementation easier to manage. Combined modules, provide high availability, advance security, QoS and easy access management. A sample network design based on enterprise network model, is presented here.

PART 2

2. A typical switching network design is represented in the below figure. We use cisco enterprise network model in this network designing. 

Here are the designing policies used in this design:

1. Starting of the network, an Edge router is placed that connect internal network to the outside network or internet. 
2. A gateway router placed next to the edge router that is responsible of additional security and campus level access control. 
3. A cisco firewall is configured after the gateway router. This firewall is configured to allow only authenticated network. NAT can also be configured for additional security.
4. The internal network is fully redundant network based on ether channel topology. 
5. We use several layer three switches to build ether channel. Ether channel provide resiliency, redundancy and fault tolerance in the network.
6. These layer three or ether switches connect layer two switches that belongs to different departments.
7. VLANs are configured on the multilayer switches or layer three switches and put them on VTP domain mode.
8. Layer two switches are configured as client mode. So that they can retrieve VLAN information from upper layer switches. 
9. On layer two switches, port connected with layer three switch is a trunk port and ports connected to the end user devices are configured to access ports.
10. Access ports are assigned a VLAN according to the placement of devices. 

3. Answers to the questions:

1. The network is not fully converged. Because it is not able to connect all nodes and hosts in the network or either unable to connect to the other nodes. As we can see in the given figure, after reaching its default gateway and direct connected router, it showing request timed out error. That shows, it is not a fully converged network.
2. The router 1, router 2 and router 3 has some missed network. Because of this, it generates the error of request timed out. The possible missed route or network on router 1 and router 2, are – 192.168.1.0 and 172.16.0.0. 
3. This network is very small network. So, we can use RIPv1 or RIPv2 routing protocol. RIPv2 is an upgraded version of old RIP protocol. This is a distance vector routing protocol and best suited for smaller networks. This protocol benefited with support of VLSM, fast convergence, support of authentication, route summarization and support triggered updates. It has a hop count limit of 15 hopes . That is sufficient for a smaller network that is shown in the figure. For example, we only have three routers in our network and limited hosts. RIPv2 will share routing updates every 30 seconds between the connected routers and share trigger updates when any sudden change in the network will see. So, its best suited to our network topology.