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IP Address for a VLAN - why?

I understand that devices on a network have IP addresses, but why do VLAN's need to have  their own IP addresses?
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brothertruffle880
Asked:
brothertruffle880
5 Solutions
 
Zephyr ICTCloud ArchitectCommented:
It''s mainly used for inter-vlan routing, separating networks...

Look at it as a separate network, the IP-address set on the VLAN-aware device (a vlan in itself doesn''t have an IP, it''s the vlan-aware device that does) is used as a "gateway" for that network (acting as a router) ...

Simply put ...
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max_the_kingCommented:
Hi,
VLAN do not have "their own IP address".
Rather they have their own subnet, because you want them to be logically separated from other subnets.
You probably wanted to know why do they are referentiated by an IP, which is another story: in fact, they may have (not mandatory though) an IP address useful for management, e.g. to be reachable on that IP from devices on the same subnet or a subnet allowed to reach that particular VLAN.

hope this clarify
max
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bbaoIT ConsultantCommented:
interesting question.

basically, different VLAN just means different physical network. as any network needs a way to differentiate itself from its counterpart network to communicate, a unique IP subnet is required.

does it make sense?
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tankergoblinCommented:
Anything you need to communicate with need an IP address and that include VLAN.. VLAN actually is a Virtual LAN and without an IP address your packet can go no where.

example:
  if one of your user pc is under VLAN then you will create a VLAN ip of 10.0.0.1 as VLAN2 for him so that when you want to send any packet to this user your router or switch know where to send to..
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MiftaulCommented:
VLAN is a Layer2 boundary which contents devices in Layer2. VLAN boundary doesnt have any Layer3 intelligence.
If you want Layer3 communications from within the VLAN boundary to go outside of the VLAN, you need some IP intelligence. Once way to have that IP intelligence for the VLAN is to configure SVI(Switches Virtual Interface), that is to configure the VLAN interface with an IP address. You can also TRUNK a switchport to pass all the VLANs to a Layer3 device and do the IP intelligence job on the Layer3 device.
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