The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] [mpls] Avoiding LDP graceful restart with planned node shutdown.
Hi, In the case where a node is to be permanently disabled in a network in an orderly manner (planned shutdown), but where normally it advertises to its LDP peers that it supports graceful restart procedures, it is desirable that peers do not use graceful restart procedures when they detect that the node has gone. This is to prevent the peers continuing to forward data to the stopped node on the assumption that the node's forwarding state is still intact. Such forwarded data will be black-holed until the peer neighbour reconnect timer expires. To prevent graceful restart usage under these circumstances requires that nodes can detect the difference between the planned and unplanned shutdown of a peer. While RFC3478 makes no specific comment on how to do so, a possible approach would be that when a node detects the failure of a peer through receipt of a Notification (shutdown), the receiving node assumes this is a planned shutdown of the peer, and disables graceful restart. In all other cases (TCP socket error, keepalive timeout etc.), the node assumes unplanned shutdown, and starts its graceful restart neighbour reconnect / liveness timer for the session. I'd like to get clarification if this is in fact the intent in the standard? Thanks, Andy. _______________________________________________ mpls mailing list mpls@lists.ietf.org https://www1.ietf.org/mailman/listinfo/mpls |
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