Okay, maybe it doesn't quite qualify as a mystery but it just occurred to me that I don't know what actually triggers a demand circuit to come up. I *thought* I did until I ran into a new scenario tonight that confused me.
In this scenario, IS-IS and OSPF are running on a router, but only one interface is participating in OSPF and that is the one configured as a demand circuit. So, under normal operations there are no OSPF routes in the routing table, only IS-IS routes. In the usual situation where OSPF is running on multiple interfaces, I assumed it was some function of OSPF that triggered the demand circuit to come up. In that situation there is an interface running OSPF that is aware that the adjacency went down and that could trigger the demand circuit. However, in this case, only IS-IS is running on the main interface. What is it that actually causes the OSPF demand circuit to come up? I don't see how it could simply be a topology change since OSPF isn't aware of the IS-IS topology. So, specifically, what is occurring? Perhaps I'm being dense but I just don't see which mechanism is responsible for this. Someone, please put me out of my misery. :-) Thanks, John ________________________________________________ Get your own "800" number Voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=34732&t=34732 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
