Subject: [rbridge] Treating broadcast addresses

From: rute.sofia at siemens.com (Sofia, Rute)
Date: Mon, 17 Oct 2005 13:06:09 +0200

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/d443347f/attachment.html