Networks Choosing Managed Gigabit Switches

I'm not planning on doing any massive upgrades just yet, but I've been keeping an eye out for how to make our network fater and more managable.

I've found a NETGEAR GS748T ProSafe 48-port Gigabit Smart Switch for around $700, but that seems kind of cheap for a 48 port Gigabit managed switch.

I've never used a managed switch before, so I was a little surprised to see this one came with fiber connectors built in.

Right now, we have fiber running between each building with a Fiber Optic Converter converting it to ethernet, which then goes into our 10/100 switches. (unmanaged)

With a managed switch, is it possible to keep the Fiber Optic Ports separated?
Meaning, can I have 2 Fiber lines going to all but 4 ports, then have another fiber line going to only 4 ports? (basically having the intranet and DMZ fed into the same device without fear of overlapping?)

Just trying to check and see how to make things run as smoothly as possible.

EDIT:
It looks like it's more expensive older brother, the NETGEAR GSM7248 ProSafe 48 Port Gigabit L2 Managed Switch has all of the fun managing features like vLAN and link aggregation, traffic prioritation, and stuff like that. But that makes me wonder why they call the first one a managed switch?

 

I don't think that switch is actually managed. It's just a "smart" switch - we use them for workgroup switches at work; they have more features than an ordinary unmanaged switch (like trunking and VLANs), but not full layer 2 or 3 features (like QoS and authentication). That's why they seem so cheap!

They are pretty good, however I've found myself wanting some of the more advanced features of layer 3 switches on the ones we use. If you have the $$$ go layer 2 or 3, if you are on a budget just go Smart!

 

"Managed" is a misnomer in this day and age. Theoretically the term simply means it supports some form of active management, usually RMON. Go back 10 years or so and all a managed L2 device gave you was maybe some port stats and SNMP if you were lucky and as time went on they started adding more and more features to the device. Nowadays it's actually the features that allow for the management - once you start implementing the silicon required for extra features that are "active" like vlans and stuff then it becomes trivial to also add the management hence any switch offering advanced features becomes "managed".

Back to the OPs question, the fiber ports on that switch are simply another Layer2 ports and can be treated exactly the same as any of the other ports on the switch - you can separate the distribution of ports to whatever vlans you like. However to correct a misconception they don't come with fiber connectors built in - what they have is an SFP slot into which you can insert GBICs that will take fibre connections [you can get copper ones too] and you will need to buy the GBICs as an additional item. Th GS748T does support vlans and some other functions but it notably seems to not support spanning tree which seems an odd omission to me.

J