Archived from groups: comp.dcom.lans.ethernet (
More info?)
max8y@yahoo.com (Max) wrote in message news:<7800b3f8.0406040635.40948814@posting.google.com>...
> >
> > > Does it mean if the bridge receive a GVRP frame on one port for VLAN
> > > X, then every port (in forwrding state) on the bridge will be memeber
> > > of VLAN X?
> >
> > At a high level, GVRP works as follows. When a GVRP frame is
> > received on a port, all of the VLANs in that frame are updated
> > to have a port set that corresponds to the port that the frame
> > was _received_ on. The set of VLANs is then propagated on
> > all ports on the spanning tree except that which the frame
> > was received on. Assuming both edges of the network have GVRP
> > running (and they have to in order for it to work), all switches
> > in the network will eventually receive GVRP frames for VLANs
> > on ports through which those VLAN's members can be reached.
> >
> This is the point I dont understand. This pretty much says that ALL
> ports on ALL bridges that can be reached in the spanning tree domain,
> will become memeber of the VALNs conveyed in the GVRP frame. That does
> not seem to be the reason we want VLAN in the LAN, or I
> misunderstood...
Consider the following example (you must view this in
fixed-width font or the pictures will get messed up).
Original configuration of VLANs on edge ports
| 1,2
+++
|A|
+++
|
|
|
+++ +++ +-+
1 |B+-----+C+-----+D| 2
+-+ +++ +-+
GVRP frame sent from A to C
| 1,2
+++
|A|
+++
|
|
|1,2
+++ +++ +-+
1 |B+-----+C+-----+D| 2
+-+ +++ +-+
GVRP frame sent from D to C
| 1,2
+++
|A|
+++
|
|
|1,2
+++ +++ +-+
1 |B+-----+C+-----+D| 2
+-+ +++ 2 +-+
GVRP frame sent from B to C
| 1,2
+++
|A|
+++
|
|
|1,2
+++ +++ +-+
1 |B+-----+C+-----+D| 2
+-+ 1 +++ 2 +-+
GVRP frame sent from C to B
| 1,2
+++
|A|
+++
|
|
|1,2
+++1,2 +++ +-+
1 |B+-----+C+-----+D| 2
+-+ 1 +++ 2 +-+
GVRP frame sent from C to D
| 1,2
+++
|A|
+++
|
|
|1,2
+++1,2 +++ 1,2+-+
1 |B+-----+C+-----+D| 2
+-+ 1 +++ 2 +-+
GVRP frame sent from C to A
| 1,2
+++
|A|
+++
|1,2
|
|1,2
+++1,2 +++ 1,2+-+
1 |B+-----+C+-----+D| 2
+-+ 1 +++ 2 +-+
As you can see, switch C has only VLAN 1 on the left
port and only VLAN 2 on the right port. This ensures
that it doesn't flood a VLAN's traffic on a port
where there are no interested receivers.
Hope this helps clarify things.
Anoop