Re: Broadcast between Vlans

aaoybe · ‎08-17-2005

Is it possible to configure broadcast to be allowed between subnets? I have a 6513 Switch centrally with all vlans.

noonanac · ‎08-17-2005

Is there a specific reason you wish to broadcast?.

A basic premise of using switched ports, switches and VLAN's is to contain broadcasts within specific segments of a network and a reduce overall load across networks.

As opposed to hubs and non-intelligent bridges which flood all traffic through a network.

aaoybe · ‎08-17-2005

Yes, i need broadcasts from a administration server in one vlan to reach modems in another vlan. The adm.server uses broadcast to communicate to the modems.

I want to move the modems to separate vlans based pr. customer and the administration server in one vlan since the administration server communicates with all modems.

noonanac · ‎08-17-2005

Hi,

I do not know of a way to do this, and I do not believe it can be done as it would seem to make the reasons for implementing a VLAN topology redundant (as from my last posting).

The only way I would consider going forward is moving the modems and servers into the same VLAN's or setting the port of either the modem or servers to be in more then one VLAN.

aaoybe · ‎08-24-2005

I got it to work doing:

Example:

"Where broadcast is forwarded from"

Interface xx

ip helper-address 10.0.1.255

ip helper-address 10.0.2.255

"This is done to select the port to forward"

ip forward-protocol udp "port"

"On the interface that receives the broadcast"

Interface xx

ip directed-broadcast "access-list number"

This worked perfect.