A service provider network is currently divided into five IGP domains; four IS-IS domains and one OSPFv2 domain.
Because of customer demand, it has been decided to implement Cisco MPLS TE tunnels using a centralized offline path calculation system.
Which method provides a way to distribute the required information to the path calculation system?
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A. B. C. D.C.
The question is asking about how to distribute information required for implementing Cisco MPLS TE tunnels using a centralized offline path calculation system across a service provider network that is divided into five IGP domains, four of which are IS-IS domains and one is an OSPFv2 domain.
Option A suggests converting the OSPFv2 domain to a new IS-IS instance. This would allow all the domains to use the same IGP, which could simplify the network design. However, this would be a significant change to the network, and may not be practical or desirable.
Option B suggests using RSVP-TE IS-IS/OSPFv2 extensions to distribute the information. RSVP-TE (Resource Reservation Protocol - Traffic Engineering) is a signaling protocol used to set up MPLS TE tunnels. IS-IS and OSPFv2 both support extensions to distribute RSVP-TE information. This option would allow the network to continue using its current IGP domains, while still being able to distribute the required information to the path calculation system.
Option C suggests using BGP LS (Border Gateway Protocol Link State) to distribute information across the domains. BGP LS is a mechanism for distributing topology and traffic engineering information between BGP speakers. While this could potentially work, it would require significant changes to the network design, as BGP is not currently being used in the network.
Option D suggests performing mutual redistribution between all IGP domains. This would allow each domain to learn the routes from the other domains, and could potentially work, but would also require significant changes to the network design. In addition, there could be issues with route flapping or suboptimal routing paths.
Overall, option B - using RSVP-TE IS-IS/OSPFv2 extensions to distribute the information - is likely the best option in this scenario, as it allows the network to continue using its current IGP domains while still being able to distribute the required information to the path calculation system.