Network design

Hi all, as part of my course, I have been given the task of redesigning a company network infrastructure (as a result of the company acquiring several small operators) in order to provide service to all of the new locations for the companies TCP/IP network. The goal is to provide the most cost effective services using all available technologies that’ll ensure efficient network utilisation, secure systems and resilent network services.

“The company is an airline company providing low-cost, efficient flights to destinations across Europe. Services they provide include; allowing ticket operations, flight planning, aircraft scheduling and crew rostering, maintenance and company wide services including intra and internet access”

Part of the design stages requires me to design an IP address structure and select appropriate routing protocols and technologies to allow seamless interconnection of service for all users.

My Question:

What is meant by ‘technologies to allow seamless interconnection of service to all users’? I don’t understand what is meant by that. Could someone clarify this for me please? Responses will be greatly appreciated. Thanks in advance.

ps: secondly, what is the current technology in the market now and could there be any implication given this block of IP address: 235.85.105.64/27 - 235.85.105.128/27 to use in the design ?

My thoughts: I intend using a Hierarchical Network Design Model i.e. core, distribution and access.... not sure about how to use the CIDR block as we have to use it for about a thousand plus PCs at different hubs...and also ensure that the network is scalable.

there's got to be someone who knows this thing. pls help

Hi there,

I am fairly new to this myself, coming from a mainly Microsoft Background but here is my suggestions to this.

I think the ‘technologies to allow seamless interconnection of service to all users’? simply means what its says. You have stated that the company services provide; Ticket Operations, flight planning, aircraft scheduling, etc... These services need to be able to be accessed by whoever requires them and it needs to be seamless, i.e. just there available to the users without messing. (well thats what i think).

I think you are along the right lines with the Hierarchical Network Deisgn Model of access layer, distribution layer and core layer. Take a look at this here

Depends how much detail you want to go to, this can be further expanded, if this is a large organisation it;

Enterprise Campus - Building Access (Layer 2 Switching), Building Distribution (Layer 3 Switching), Campus Backdone (very high speed layer 3 switching), Server Farm and network management sections.
Edge Distribution - Layer 3 switching to link the Enterprise Campus into the Enterprise Edge
Enterprise Edge - E-commerce Module, Internet Connectivity, Remote Access VPN & WAN
Service Provider Edge - Links to the Enterprise Edge providing ISP, PSTN and ATM/PPP/Frame Relay

Finally, your CIDR would work in the core modules. If you have layer 3 addresses in your Building Access (layer 2) modules.

Taking your example address (well sort of). The /27 subnet will give you chunks of 32 host addresses.

Therefore you will have 0-31 (cannot be used, although these days with subnet zero it can), 32-63, 64-95, etc... This will look like

235.85.105.0 - 235.85.105.31 (not used)
235.85.105.32 - 235.85.105.63 - First Address
235.85.105.64 - 235.85.105.95 - Second Address
etc...

So, with CIDR, if you ensure that these addresses are along the same path you are are using the fully 512 address in that range (i.e. Class c), you can have a route for 235.85.105.0/24 in the Campus Backbone forwarding this traffic to the Building Distribution, instead of specifying each address.

Hope it makes sense but this is my 2 penny.

Cheers

Just remember, CIDR can be used to consolodate routes for varying subnets, mine above was just an example.

If you have subnets with /27. Depending on which ranges you use you can consolodate to almost anything using a smaller subnet. i.e. can consolodate /27's into /26's or if you are using more in the range then it may possibly have to go to a /25. And so on.

Cheers