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Community Member

VLAN versus Proper IP Subnetting

Hi, All

I would like to know what are the diffrences creating VLAN's instead of using subnetting.

Let say I have about 200 users in each remote site, and about 300-400 in a few other remote sites. Can I just subnet my network accordingly without using VLAN's , in this way I can still separate my broadcast domains via my router int.

Is this a good solution ? What are the advantages of using VLAN in this case ?



Cisco Employee

Re: VLAN versus Proper IP Subnetting

I'm assuming that if you are not using VLANs, you'll be using secondary addresses on a routers ethernet interface. The best design would be to implement VLANs. With VLANs, each VLAN will be a subnet of it's own and limits broadcast domains

Community Member

Re: VLAN versus Proper IP Subnetting

VLANs are used when you have clients on the same switch that are not part of the same subnet. This can be done for several reasons. For example, we have users on my network (I manage a county network) that work for our state. We provide connectivity, through our network, to the state network so they can access their file servers and use the state's Internet connection. Their computers are connected to switches right along side users on my network. I use VLANs in this case to separate the two networks and provide security for mine.

Another example would be a layer 2 switch with a high port density, such as a 4006 with several 48 port cards. You could use VLANs to break up the broadcast domains (which I believe is the most popular reason). You don't necessarily want all the broadcast traffic that could potentially be created running amok all over your network.

With or without VLANs though, you are going to have to implement proper subnetting. In an IP network, there is no way around it. Good luck.

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