The IESG has approved the following document: - 'OSPF Graceful Link shutdown' (draft-ietf-ospf-link-overload-16.txt) as Proposed Standard This document is the product of the Open Shortest Path First IGP Working Group. The IESG contact persons are Alvaro Retana, Alia Atlas and Deborah Brungard. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-ospf-link-overload/ Technical Summary When a link is being prepared to be taken out of service, the traffic needs to be diverted from both ends of the link. Increasing the metric to the highest value on one side of the link is not sufficient to divert the traffic flowing in the other direction. It is useful for routers in an OSPFv2 or OSPFv3 routing domain to be able to advertise a link as being in a graceful-shutdown state to indicate impending maintenance activity on the link. This information can be used by the network devices to re-route the traffic effectively. This document describes the protocol extensions to disseminate graceful-link-shutdown information in OSPFv2 and OSPFv3. Working Group Summary There was considerable discussion on both the use case and whether we could use signaling amongst the routers on the link. However, this would not allow a controller to be informed. Additionally, there was discussion as to whether this could simply inferred from a high forward metric. After some discussion, it was agreed explicit signaling was preferred. Additionally, there was some intertwining of requirements with the signaling of other OSPF link attributes. Now that these are resolved we can move forward with this draft. Document Quality This document has been a WG document for more a year. There have been several iterations due to the controversy over area-wide versus neighbor signaling. Now that we have reached consensus, the document is fairly stable from a protocol standpoint. There has been some discussion on the use cases and they have been refined in the current version. Personnel Acee Lindem is the Document Shepherd. Alia Atlas is the Responsible Area Director.
