SVI for VLAN's

MAC20

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Feb 10, 2014
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got a quick question. I know when you create a switch you have the management vlan that has an SVI for management. But the question i have is when you create extra vlans say for voice, or networks for hand held scanners do you still need to create an SVI for that vlan as well?

as long as the vlans are on every switch in your network and your router knows these vlans as well then you should be able to communicate with other devices on the same vlan but on different switches. so what is the need of an svi for each vlan on every switch if each switch has its default management svi? Trying not to have to create 15 SVI's
 

George Mulligan

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Sep 20, 2014
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Don't understand your question...are you speaking of virtual switches? An SVI simply provides Layer 3 routing capability (and hence VLANs) for Layer 2 switches. A layer 3 switch has routing capability built in. Can you better describe your situation?
 

MAC20

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Feb 10, 2014
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SVI in terms of example

VLAN 60 (created for whatever)
then
interface vlan60
ip address x.x.x.x x.x.x.x

you dont have to create these on every switch for each vlan you create

if i have VLAN 60 on 5 switches do i need to create a interface vlan 60 on each switch as well if i already have vlan 80 (management vlan) on each switch with interfaces?

little more clarity
switch 1 has vlan 80 management at interface vlan80 ip x.x.x.1/24, also has vlan 60 for scanners with interface vlan60 x.x.2.1/24 and dhcp pool of x.x.2.0/24 for scanners

switch 2 has vlan 80 management at interface vlan80 ip x.x.x.2/24, also has vlan 60 for scanners
switch 3 has vlan 80 management at interface vlan80 ip x.x.x.3/24, also has vlan 60 for scanners

since switch one is the core and its hosting dhcp and knows each vlan the switches that are trucked off the core do not need interfaces for vlan60 since they know the default gateway is the first switch? they just need the vlan created right?

 
You only really need SVI on switch that you intend to route data between the vlans. Now I suppose you could define them but disable routing between the vlans and they would act as a management interface via that vlan. Some switch though only allow you do manage the switch on a single vlan.

Pretty much you only define them on switches you intend to act as a layer3 switch..ie router.
 

MAC20

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Feb 10, 2014
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thanks thats what i figured just was making sure. Someone told me you needed an interface for each vlan on each switch and my argument was as long as the core knows each vlan and has a dhcp pool setup for that vlan then the other trunked switches only need the vlan created.