Subject: [rbridge] Treating broadcast addresses

From: rute.sofia at siemens.com (Sofia, Rute)
Date: Mon, 17 Oct 2005 13:52:48 +0200

Vishwas,
 
Suppose you are speaking about the ST that Rbridges use to perform
broadcast. You don't need root election: the info provided by LSPs is
enough to build the ST.
 
Regards,
Rute

________________________________

	From: rbridge-bounces at postel.org
[mailto:rbridge-bounces at postel.org] On Behalf Of Vishwas Manral
	Sent: Monday, October 17, 2005 1:27 PM
	To: Developing a hybrid router/bridge.
	Subject: Re: [rbridge] Treating broadcast addresses

	Hi Rute,

	Would this also mean Root-Election? What about convergence of
this tree?

	Thanks,

	Vishwas

________________________________

	From: rbridge-bounces at postel.org
[mailto:rbridge-bounces at postel.org] On Behalf Of Sofia, Rute
	Sent: Monday, October 17, 2005 4:36 PM
	To: Developing a hybrid router/bridge.
	Subject: Re: [rbridge] Treating broadcast addresses

	Vishwas,

	based on the information exchanged by LSPs you can simply
compute the ST locally. The key here is the choice of the root. This can
also be passed along by IS-IS...

	Regards,

	Rute

		Hi,

		My question is more like, how would we build a spanning
tree for broadcast using IS-IS? 

		We need a globally coordinated tree like STP and not
like the way IS-IS computes it. Would we require, changes to the
spanning tree computation itself?

		Thanks,

		Vishwas

________________________________

		From: rbridge-bounces at postel.org
[mailto:rbridge-bounces at postel.org] On Behalf Of Vishwas Manral
		Sent: Monday, October 17, 2005 11:41 AM
		To: Developing a hybrid router/bridge.
		Subject: [rbridge] Treating broadcast addresses

		Hi,

		I had a doubt about treatment of broadcast addresses.

		Currently using STP we have one tree and ports are
blocked/ forwarding, so packets cannot loop irrespective of destination
addresses. In IS-IS protocol, we use ports based on destination address
and no ports are blocked or unblocked. But if the destination address is
FF-FF-FF-FF-FF-FF we could end in a forwarding loop. How would we get
over it?

		Would we still allow broadcast destination address
packets to be forwarded? It is like preventing flooding loops in a case
where we have a global broadcast IP address, which is forwarded to all
attached routers. Am I missing the point all together?

		Thanks,

		Vishwas

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.postel.org/pipermail/rbridge/attachments/20051017/82a915cb/attachment.html