Operation Manual – BFD-GR
H3C S3610&S5510 Series Ethernet Switches
Chapter 2 GR
2-2
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GR Session: A Graceful Restart session, which is the negotiation between the GR
Restarter and the GR Helper. A GR session includes restart notification and
communications across restart. Through this session, GR Restarter and GR
Helper can know the GR capability of each other.
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GR Time: The time taken for the GR Restarter and the GR Helper to establish a
session between them. Upon detection of the down state of a neighbor, the GR
Helper will preserve the topology and routing information sent from the GR
Restarter for a period as specified by the GR Time.
2.3 Graceful Restart Communication Procedure
Configure a device as GR Restarter in a network. This device and its GR Helper must
support GR or be GR capable. Thus, when GR Restarter restarts, its GR Helper can
know its restart process.
Note:
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In some cases, GR Restarter and GR Helper can replace with each other.
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If a router is to act as a Graceful Restarter, it must have the ability to preserve the
routing information in the routing table (forwarding table). Routers that fail to meet
this can only act as a GR Helper.
The communication procedure between the GR Restarter and the GR Helper works as
follows:
1)
A GR session is established between the GR Restarter and the GR Helper.
Figure 2-1
A GR session is established between the GR Restarter and the GR Helper
