Can Two switches pass different Vlan traffic between each other without a Layer 3 device ?

[MAnoj Kumar]

Can Two switches pass different Vlan traffic between each other without a Layer 3 device ?

[Ankur Arora]

Hi,

You can configure a trunk link between the two switches and pass multiple vlans via that link, if you want those vlans to communicate with eachother, you can run intervlan routing in the switches by creating SVIs for those vlans.

Thanks

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[oflanagan · Accepted solution]

Hello,

As you probably know layer 2 devices work at MAC address level so the switch will be able to transport data between end devices if they are on the same ip address range and subnet, When creating a Vlan you are creating a new Virtual LAN which in turn will require a new i.p address range so the use of a layer 3 devices would need the sub interfaces creating to manage the routing of data between the two vlans.

Please see link

http://www.ciscopress.com/articles/article.asp?p=1745631&seqNum=3

Hope this helps,

Oliver.

[Leo Laohoo]

Yes.  It's possible to pass different VLANs to another switch.  The main thing is this:  The different VLANs can't talk to each other.  In other words, VLAN 10 can talk to VLAN 10 only and CANNOT talk to any other VLANs but VLAN 10.

[Joseph W. Doherty]

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Posting

Depends what you mean by passing traffic between the switches.

Normally, as noted by other posters, VLAN capable switches pass VLANs traffic between them on a trunk port.  The trunk port, generally, assigns VLAN tags to frames, so that the receiving switch "knows" what VLAN incoming frames belong to.  This allows the two (or more) switches to send frames within the desired VLAN across multiple switches; VLAN frames will not be "visible" to other VLANs.

You can also extend VLANs, between switches, by using one access port, per VLAN.  Normally, you want to insure the same VLAN is assigned on the two switches connected ports.  Again, frames will be isolated per VLAN.  The disadvantages of this approach, you can only share one VLAN per port and you might mix up VLAN traffic as you cross switches.

Using the latter approach, it's possible to have the VLAN traffic in different numbered VLANs per switch, but it's just as isolated.  For example VLAN 10 port on one switch could connect to VLAN 100 port on another switch.  The two different VLAN numbered traffic will then intermix.  If their L3 is for the same subnet, the result will be one common subnet, just known by different VLAN numbers.  If the subnets, though, are different, hosts will ignore unicast addresses from the other subnet.

[a.yazdani]

hi

as I know we can do it with 2960 !

You just need 12.2(55) or later and change your SDM (switch database management) .

for more info:

http://blog.alwaysthenetwork.com/tutorials/2960s-can-route/