P2MP LSP: Re-merge

You can configure the no re-merge behavior on P2MP LSPs by enabling the newly introduced no-re-merge and no-p2mp-re-merge CLI commands at the ingress (headend) and transit devices (re-merge nodes), respectively. Remerge occurs when two or more sub-LSPs of different penultimate hops share a common downstream next hop. In order to avoid duplicate packets, the remerge condition requires that the remerging router accept or select one of the incoming paths and disregard other paths. The active penultimate hop is switched to one of the previously discarded paths if the current active path is deleted. You can change the default re-merge behavior on RSVP P2MP LSP. On the ingress (headend router), disable the default re-merge behavior so that the ingress router does not do the path computation of sub LSPs which creates the re-merge condition. The default behavior allows the path computation of sub LSPs. On the transit router, disable the default re-merge behavior so that the transit router rejects the re-merge of sub LSPs.