2950 and VLAN's

[Jeff Harned]

Hi All,

I am using one 2950 switch to route multicast data from two "source units" to three "destination units".  One source unit has an assigned multicast address of 239.1.1.3 with the other assigned 239.1.1.4.  The three destination units are configured to be able to receive both multicast data.  I am trying

to configure the switch so that I can select just one of the multicast data reaching a fastEthernet port to any one of three "destination" units I select.  I have tried using MVR, VLAN, and IGMP with some success.  At this point I still have both multicast data going to all the destination devices.

I do not have much experience but surely have gained some in this long process!!  I want to be able to use a VLAN configuration in doing this.
One of my question is this, can I do a VLAN configuration using one switch to achieve my goal?  If I can, please I need a little guidance!!

If I can not, is there another way?

Note:  I do not have a router that I can use for trunking, I have to be able to use just one switch if I can.  A basic block diagram is attached.

Thanks.

Regards,

Jeff

[cadet alain]

Hi,

maybe this is what you want if I understood your problem correctly.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a008059a9df.shtml#solu4

Regards.

Alain

[Jeff Harned]

Hi,

I am really new to this and have been learning on the go with this issue that has been with me for a while now.  Your link to the site is something I do not know.  When I do a "show mac-address-table dynamic" what I get are mac addresses for the two "source" units under vlan 1; ports 7 and 24 as shown in my original diagram. In my configuration I am not using Vlan 1.

However, these two mac-addresses do not match the mac address assigned to these two units.  Again, all I am trying to do is be able to select which mulicast address is passed to any "destination" unit I select.  Perhaps you can explain in simpler terms what this mac addressing is all about.

Thanks.

Regards,

Jeff

[cadet alain]

Hi,

Let's try to understand what is exactly your problem.

So you're sending multicast traffic  for different multicast group and you don't want traffic destined for one group to be flooded  but just sent to the machines listening for that group ?

Do I understand correctly ? If so then a L3 multicast address maps to a L2 multicast address( 01:5e:00:xx:xx:xx) and to do this when a host is listening for a L3 multicast group it will listens for frames sent to the L2 multicast address mapped from the L3 address( with the last 23 bits from IP going into xxxxxx with the first bit set to 0).

By default a switch will flood all frames destined for multicast L2 addresses but if you statically tell your switch on which port in which VLAN is the destination multicast L2 address then you won't have no more flooding and that's what the link was about.Of course there are dynamic ways to achieve this like : IGMP snooping, CGMP.

Regards.

Alain

[Jeff Harned]

Hi,

Let's see If I can expalin better.  Please look at the original diagram of my setup. 

The five units in my setup are data conversion units.  These units in this configuration will convert Serial to LAN and then back to Serial data.  I just randomally chose 239.1 1.3 and 239.1.1.4 as the coverted serial data to multicast data streams entering the switch from the "source" units.  Yes, there is a lot of data entering ports 7 and 24 (source ports) on the switch.  The "destination" units I have programmed to accept both of these mulicast data streams (239.1.1.3 and 239.1.1.4).

What I expect to happen now is this massive flood of multicast data coming out of ports 1, 13, and 19 of the switch to their respective destination unit.  All three destination units, since they were preprogarmed will now accept and convert both mutlicast data streams.

What I want to do and I would like to try using VLANs is to be able through the configuration of the switch to select any one of the two multicast data through any switch ports (1, 13, 19) to their respective destination unit I choose.  By doing this then only one of the multicast data will enter a destination unit(s).

I am new to networking and have spent a great amont of time on this. I have come close but not yet.  I want to try using VLANs because of the great isolation property it has when using mutliple ports.  I also have tried using MVR and IGMP.  Again, being new to this I must be missing something in my configuration.

Thanks.

Regards,

Jeff

Message was edited by: Jeff Harned