some advice needed.
Got a WAN, 3 buildings, main building has 3 floors, others have 1.
100 odd pcs
3 Routers
5 Switches
5 Servers
6 Departments.
Now Ive got to use VLSM and VLANs, but if I put every department on its own subnet, would I need to vlan them?
Or is it a better idea to be putting each building/Floor on its own subnet, and then using the vlans for each department?
i would put each floor on its own subnet an create a vlan for each floor that way the departments on one floor donot have to contantly dial into another department just to share its resources. + if the vlan went down on a floor it would be better off than every deparment not accessing each other. in my opinion any how !
You cant have one subnet over more than 1 vlan, but you can have more than one subnet per vlan but it will make it very difficult to run DHCP.
Using the Cisco model each department would have a separate Vlan and subnet, thus allowing for department resources to be secured. One router per building. and one switch for each of the sub offices. That leaves one switch per floor. Assuming you dont have a layer 3 switch youll need to trunk between the switch in the main building and the router to provide inter-vlan routing. Then Put the servers in a separate vlan unless there are servers with specific purposes (i.e. a special finance one and an MP3+UT2004 server for the IT department) which would ideally go into the same VLAN as that department.
All the switches in the main building are linked together with trunks.
Is this for Cisco or a Degree?
Quote from: Poison_UKIs this for Cisco or a Degree?
both! haha its my degree assignment but were using cisco scenario.
Porch Monkey cheers that clears things up quite a bit!
Silly question time...
Ive read the word "trunks" in quite a few networking threads and I have assumed that it means physical cabling (of some description). Is that right ?
dunno if its right but my take on trunks is connections between switches.
Its usually used to describe not a single physical connection but a large bundle of them.
ahhh and is where the name "trunking" comes from for the conduit that the cables are usually laid into !
Clear as mud :D
remember your ip-helper addresses !!!
a trunk is where if you have a number of vlans on a switch, which is connected lets say to a router, the connection between the switch and the router is a trunk, it allows all traffic through, regardless of which vlan its on.
Ports on a switch are either assigned to a specific vlan (0 default) or are made into a trunk.
Which just goes to show there are a hell of a lot of different uses of the word trunk ;)
Just had a look on Wikipedia.
I think the reason Im getting confused by this is porbably becuase the last time I was reading the Cisco curriculum was back in january. But from what I remember Porch Monkey is pretty much spot on with the Cisco way of doing things.
In switch/network terms a trunk is an interface that can send a recieve packets on more than one vlan. VLAN1 is the default vlan on cisco kit and as such also hold some special properties.
If you have more than one vlan on a switch you can tell one port to be a trunk either through 802.1q (industry standard) or if its all Cisco kit you can use ISL which is proprietary.
Between switches trunks allow traffic from one vlan on one switch to access ports on another switch on the same vlan. If you trunk to a router you can then create virtual interfaces on that router corresponding to the each vlan and then route traffic between them.
If you have more than one physical connection between two devices its called a bundle or Ether-channel for ethernet interfaces on cisco kit. (This has to be configured to become a channel otherwise spanning tree will stop all but one interface from working but Im not about to get into that particular can of worms.)
Quote from: Porch MonkeyIf you trunk to a router you can then create virtual interfaces on that router corresponding to the each vlan and then route traffic between them.
Is this another term for a sub-interface? cos I havent read up on them yet but I need to use them for the exact same reasons you mentioned.
Yes, its the same thing.