 | Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |
PIM sparse mode uses a mechanism called a generation identifier to indicate the need for graceful restart. Generation identifiers are included by default in PIM hello messages. An initial generation identifier is created by each PIM neighbor to establish device capabilities. When one of the PIM neighbors restarts, it sends a new generation identifier to its neighbors. All neighbors that support graceful restart and are connected by point-to-point links assist by sending multicast updates to the restarting neighbor.
The restart phase completes when either the PIM state becomes stable or when the restart interval timer expires. If the neighbors do not support graceful restart or connect to each other using multipoint interfaces, the restarting router uses the restart interval timer to define the restart period.
| Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |