|
Posted by on October 7, 2007, 12:56 pm
If you were Registered and logged in, you could reply and use other advanced thread options > On Oct 5, 1:28 pm, ramcnei...@gmail.com wrote:
>
> > Hello,
>
> > I would just like to confirm. If I want to setup VLANS using a Layer
> > 2 switch, I would also require a router to be added to the setup and
> > with a Layer 3 switch, I'll need no router.
>
> > Thanks for any help in advance.
>
> I think the confusion is caused by the terminology.
>
> VLANs operate at layer 2. VLANs are virtually separated layer 2
> nets.You can use VLANs just like any two or more physically separate
> layer two networks, with or without a router to tie them all together.
>
> In principle, there's no need for routers UNLESS you want to tie
> together separate layer 2 nets. So the same applies to VLANs. No need
> for a router UNLESS you want hosts on separate VLANs to be able to
> communicate with each other.
>
> A "layer 3 switch" *IS* a router. So by definition, if hosts in
> different VLANs must be able to communicate with each other, you will
> need a router, or a layer 3 switch, or call this layer 3 box whatever
> else some marketer dreams up next.
>
> A router may be "VLAN aware," meaning that the Ethernet interfaces of
> the router are capable of decoding the 802.1Q extensions of the
> Ethernet header. It's perfectly okay to call such a box a "router."
>
> And some routers provide some interface ports which are bridged
> together, meaning that the hosts connected to this subset of its
> interfaces belong to the same IP subnet. So a box like this is
> actually a combination of Ethernet switch (layer 2 switch) and IP
> router (layer 3 switch).
>
> Bert
Thanks Bert for clearing that up.
|