Keeping IP handsets (I think these are IP phones) in a seperate network is always better idea. Also PC's (user computers) and Servers needs to be seperated as users work on computers and servers will be managed by only Admins and should not be accessible users.
So you need to have three seperate networks IP phones, user PC's and Servers.
What you can do is, if you are sure that IP phones, user pc's and servers are not morethan 254 I mean /24 network then Yes you can devide the existing network. In this way you may need to change the IP address of each ones (if some are fall in the same allocated network then you can just change their default gateway)
If you are not sure that all are only 254 or less then you can use seperate /24 network for each one like...
10.10.28.0/24 for IP phones 10.10.29.0/24 for user PC's 10.10.30.0/24 for Servers Of course this is the best idea as may be in future your network can expand.
Now to create a VLAN's in 3750 switch, please see the below links.
Generally speaking it is a good idea to separate IP phones and PCs by using VLANs. You can also separate your servers if you want. It is crucial to understand, though, that there will be no communication between VLANs so if you are going to use VLANs you will need to set up some kind of routing device to route traffic between them. A server can do this, or a router or a layer 3 switch like your 3750. If you follow the logic of this you will see that you need a separate subnet for each VLAN, otherwise the router will not know to route the packets. If you cannot accomodate separate subnets because of your corporate policies then I think that this change cannot be done.
You could consider creating a VLAN for phones that the rest of the corporate network cannot route to by using a private IP range that is not in use elsewhere on the network. Obviously, you would want to discuss this with the network manager first. Often IP phones have a two port switch to accomodate a daisy-chained PC. In this case you can get the phone to select the phone VLAN for itself and pass on the 'normal' LAN to the PC.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.