RE: LAN Design

[scott_mchale]

Guys,

Please help!!

Part of mu course work for University

I have a three floor admin building which houses 300 staff with the possiblity of another 90 over the next three years. Top floor houses the admin team, the remaining two floors house the customer service team. At present the LAN has three network segments connecting to a single router in the building,

with either a 10Mbps or 100Mps switch on each floor. Cabling is copper throughout, and the wiring plan has evolved in an adhoc way over a number of years. There appears to be no redundancy within the wiring. The servers are within the same network segment as some of the staff

computers. I need to design a LAN upgrade that will be able to support the above, but am finding this a lttle difficult..

Any help would be greatly appreciated

Thanks

Scott

[mheusing]

Hi Scott,

Have a look at the Solution Reference Network Design Guides, namely

LAN Baseline Architecture Overview--Branch Office Network

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns551/c649/ccmigration_09186a00806fe216.pdf

and

LAN Baseline Architecture Branch Office Network Reference Design Guide

http://www.cisco.com/application/pdf/en/us/guest/netsol/ns551/c649/ccmigration_09186a00806fe245.pdf

They will give you best practice recommendations for LAN designs, which looks like what you need.

Hope this helps! Please use the rating system.

Regards, Martin

P.S.: Further guides can be found at www.cisco.com/go/srnd

[Rick Morris]

As posted already the SRND is a great resource, but may not be practicle for all applications.

You have some unknown factors that play into your issue.

Do you have any budget to work with?

Are you suppose to use what you have or can you add to it or replace it?

These are important things to know moving forward.

What do you have in place today? Switch type, router type, catagory cable type, any fiber at all, need for redundancy?

[scott_mchale]

Hi,

The aim is produce a cost effective solution. I am not required to give specific costings.

My upgarde solution should be sufficient for an increase of 150% traffic, should optimise performance and use of resources. Any additons to the network must be justified.The document does not states any equipment being used at the moment.

To let you understand this is one of the main headquaters, the other being Birmingham. The analysis and findings from the current network below:

LANS

Glasgow's LAN has three network segments connecting to a single router in the larger building,with either a 10Mbps or 100Mps switch on each floor. Cabling is copper throughout, and the wiring plan has evolved in an adhoc

way over a number of years. There appears to be no redundancy within the wiring. There is currently no network infrastructure in the warehouse building. The Glasgow servers are within the same network segment as some of the staff computers. Birmingham's LAN has a single network segment. LAN performance within the main sites is unsatisfactory due to excessive traffic within many parts of the network, and reliability is poor.

Glasgow LAN requirements

Glasgow (Main Site)

• At present 300 staff (50 Warehouse, 150 Customer services, 100 staff finance/admin)

• Site is split across two buildings (Warehouse & 3 floor Admin building)

• Finance/Admin staff located on the top floor of admin building

• Finance/Admin staff authorised to access payroll & personal data

• Customer service staff located on two remaining floors of admin building.

• Networked PCs for all staff

• Warehouse staff, to share desktop PCs

• Copy of full database, stored at this location

• Web Server cluster located on site

• Internet Access

• Warehouse staff not permitted Internet access

• Use public class C network 195.168.0.0 for all internal addressing

• To minimise wasted addressing space, VLSM to be used

• Expect 150% growth of current IP requirements

• Expect 30% growth of work force

Does this help any

Thanks

[Rick Morris]

Quick and dirty recommendation would be to replace all IDF switches with 4500 series switches. All capable of doing layer 3. This will be your access layer.

All feeding back to a Data Center, MDF, locaiton to another 4500 used as your distro layer, which is then connected to your router, your core layer.

In the distrobution layer you will connect servers in the DC and dual feed all the IDF's to either two 4500 distro switches or dual supervisor engines in the one chassis.

For all servers you will dual home them into 2 different chassis or cards.

Replace copper uplinks with dual fiber runs.

You could get away with running 3750G stacks in the IDF's. This allows for single control of the entire switch stack and not seperate devices which will save some of the cost of going for the big guy of the 4500's. You can build VLAN's to allow access to only specific networks and restrict Internet access to only those allowed to access.

This will give you a high bandwidth and high availability in your design. This is very high level but should help point you in the right direction.