Designing Network Topolgy

ednard

Hi guys,

I'm creating a mock up of a network, however I don't have experience of designing networks above 8-20 users such as the practice PT tests and scenarios. I've not done a lot of CCNA level stuff in the past twelve months due to other commitments, but I've decided to do a networking project for university but I'm really struggling with designing the topology and would appreciate some help.

The network is going to be 109 users large, split into around 12 different departments. For the sake of tidyness, I'll be putting two departments per 24-port switch and allowing 11 ports per department, however I'll be using VLAN's and VTP so any expansion of a department past the 11 assigned ports can be connected to any switch and still function.

This is the bit I am stuck on, however. I'm familiar with using routers for inter-VLAN routing, or just using ROAS, however I've never designed a basic network of this size in which I am trying to create a lot of redundancy into in the distribution and core layers, so I'm stuck at the best route to investigate, and would appreciate some help. This is the topology thus far:

Please note, 1 PC represents a workgroup of around 6-22



Like I said, I've got very limited experience with actually designing and creating topologies, and a just looking for maybe some ideas of more effective ways of doing this, or criticisms of what I've done and why it's bad? Any constructive replies will be highly appreciated.

xnx

Take a look at my Home Lab page page (link PMd), I use the topology for CCNP Tshoot with some adjustments. I've also designed one for university last year, please PM me and i'll send you it - don't want any of this public as they all have my full name on and university etc.

I'd use link aggregation for each cable, so that each cable would become a pair. I'd also use multi-layer switches and ACLs to control traffic flow. Also be very careful with VTP as it's easy to overwrite / delete VLANs

ednard

PM'd, thanks.

In regards to the topology, I like the idea of link aggregation and is something I've got down on my list of 'possibly implement', I'll do some background reading on that. Would you advise this from the Distribution layer switches to the access layer switches, too?

azaghul

My 2c

• Don't discount going to a collapsed core (combined distribution/core layers) for simplicity, having them separate can just complicate things depending on the network size.
• Look to using aggregation (or distribution) switches for multi-switch locations (eg: a building distribution switch with access switches for each floor).
• Don't over design, as redundancy comes at a $ cost. We run a mix of 2950/2960/3750 switches (400+ across 40 sites), and I've only seen 1 die in 3 years. But extra fibre cores between locations is ALWAYS required. Cold replacing a switch is relatively cheap & fast, getting a new fibre run in...yuk.

ednard

azaghul wrote: »

My 2c

• Don't discount going to a collapsed core (combined distribution/core layers) for simplicity, having them separate can just complicate things depending on the network size.
• Look to using aggregation (or distribution) switches for multi-switch locations (eg: a building distribution switch with access switches for each floor).
• Don't over design, as redundancy comes at a $ cost. We run a mix of 2950/2960/3750 switches (400+ across 40 sites), and I've only seen 1 die in 3 years. But extra fibre cores between locations is ALWAYS required. Cold replacing a switch is relatively cheap & fast, getting a new fibre run in...yuk.

Thanks for the input. I'm considering collapsing it, I'm just planning it at the moment and am trying to get some advice on what may be simpler and most efficient, so I'll definitely look into the benefits of that and see what I find.

Hondabuff

Is this for a fake network you are trying to build or is it for a real project?

ednard

It's just a made up network that doesn't have any limitations in regards to cost or time.