Small Business Subnetting

Unanswered Question
Mar 15th, 2007
User Badges:

I have been tasked with running the network for a small company of about 10 people and several remote workers. We have about 20 IP phones, 20 computers, a 4006 switch w/ RSM and a 3845. Everything at the moment is all on the same subnet. For security I would like to move the phones on their own subnet. This brings the question of subnetting everything else. From the CCNA I know HOW to subnet but it is a different story to put this into practice. What is the typical scenario for subnetting a company this size? Should I put execs in a different subnet for security? Remote users in a different subnet? One thing I am sure of is that the IP phones should be on their own subnet. Any help is greatly apprecieated.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
mheusinger Thu, 03/15/2007 - 08:55
User Badges:
  • Green, 3000 points or more


you already mentioned one reason to separate hosts into different groups: security. another reason could be excessive broadcasts.

With only 10 people I would create one subnet for their PCs -> subnet 1. If additional security is required (for execs), I would implement private VLANs.

Phones separate -> subnet 2

Remote workers -> subnet 3

You will need a separate subnet just for routing purposes for remote workers.

Servers? Might require an ACL between users and servers for security -> subnet 4

Be careful though, some applications assume clients and server in the same VLAN.

Check your requirements and also additional equipment around.

For simplicity assign a private subnet with /24 to each VLAN like 10.1.x.0/24 with x=1,2,3,4,...

Hope this helps!

Regards, Martin

r3alityc0d3r Thu, 03/15/2007 - 09:12
User Badges:

That makes sense. I was going to go with a 192.168.10.x subnets. That got to be really difficult since i was trying VLSM and fitting everything in one small space. Since i have to account for growth the 10.1.x.0 ip space can help. 10.1.x.x can be for one location while 10.2.x.x can be for another location. Thanks for you answer. It helps me out imensly.

bala.subramanian Wed, 06/13/2007 - 08:14
User Badges:

In addition to asking the questions you have raised, one would want to answer the following questions: Are productivity and speed affected when subnets are created?; Is there an optimal or maximum number of subnets? What happens when there are more than one subnet in which members/users belong to?


This Discussion