Solved: Question On Number Of Devices In A VLAN

dholder · ‎12-17-2007

I am looking at our server farm VLAN, and think we are getting close to some limitions. I have heard of a 50% rule, which in our case, a 22-bit should have no more then 512 devices in that VLAN. We are currently at 555 and they are getting ready to add about 60 more severs.

Is there such a rule/limitation?

I want to divide the current VLAN into a Medical Application VLAN and Office Application VLAN.

Any assistance on this would be appreciated.

Dave

Jon Marshall · ‎12-17-2007

Hi Dave

Different people give different answers and there are no hard and fast rules about this but i would not go above a class C for any vlan usually although a lot depends on the amount of broacast traffic on that vlan which can be applicaiton dependant.

On a server vlan i would generally look to use /25's at most although it does depend whether there is a logical separation in terms of function ie. you mention a medical application vlan and an office vlan.

if you can split the vlan up into these 2 functions then i would recommend you go down that route. Also there is nothing wrong with having 2 or 3 vlans each with it's own subnet range per function.

I would try to avoid using anything over a class C for pretty much any vlan but server vlans as suggested i would go down to /25's.

HTH

Jon

View solution in original post

Jon Marshall · ‎12-17-2007

Hi Dave

Different people give different answers and there are no hard and fast rules about this but i would not go above a class C for any vlan usually although a lot depends on the amount of broacast traffic on that vlan which can be applicaiton dependant.

On a server vlan i would generally look to use /25's at most although it does depend whether there is a logical separation in terms of function ie. you mention a medical application vlan and an office vlan.

if you can split the vlan up into these 2 functions then i would recommend you go down that route. Also there is nothing wrong with having 2 or 3 vlans each with it's own subnet range per function.

I would try to avoid using anything over a class C for pretty much any vlan but server vlans as suggested i would go down to /25's.

HTH

Jon

dholder · ‎12-18-2007

Jon,

Thanks for the input. In looking at our server farm this really should not be an issue, except in the Medical Applications VLAN. Even that exception would make it acceptable.

Thanks again for the assistance.

Dave