Layer 3-VLANs

information_science · ‎06-02-2009

Hello,

the product description of the Catalyst 3560 says that this switch Multilayer switches can look deeper into the frame => intelligent decisions

based on Layer 3 or Layer 4 information.

So is it possible to create VLANs based on Layer 3 dynamic by the IP Adress instead of the MAC Adress?

Greetings from Germany!

BrinksArgentina · ‎06-02-2009

No, because TCP/IP is a stack, you can't read L3 info if L2 doesn't exist (VLAN not created)

information_science · ‎06-02-2009

Somewhere I read:

'The Network Address Based VLAN links subnets according to the source IP address of the datagrams. This type of solution provides great flexibility insofar as the configuration of the switches changes automatically when a station is moved. On the other hand there may be slight degradation in performance since the information contained in the packets must be analysed more closely. '

So, this is wrong? Or do I need something special to configure this function?

Amit Singh · ‎06-02-2009

I think you are referring to protocol based vlans here. Please see the link below :

http://en.wikipedia.org/wiki/VLAN

If yes, then Cisco switches doesnot support protocol based vlans.

HTH

information_science · ‎06-02-2009

Yes, that's right.

Is there any reason, why they don't support protocol based vlans?

So I have to use the Dynamic VLAN based on the MAC address?

Amit Singh · ‎06-02-2009

May be because it might use more resources from the switch.