Graceful restart, Commands in this chapter – Dell POWEREDGE M1000E User Manual
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OSPF Commands
Graceful Restart
The PowerConnect implementation of OSPFv2 supports graceful restart as
specified in RFC 3623. Graceful restart works in concert with PowerConnect
nonstop forwarding to enable the hardware to continue forwarding IPv4
packets using OSPFv2 routes while a backup unit takes over management
unit responsibility. When OSPF executes a graceful restart, it informs its
neighbors that the OSPF control plane is restarting, but that it will be back
shortly. Helpful neighbors continue to advertise to the rest of the network
that they have full adjacencies with the restarting router, avoiding
announcement of a topology change and everything that goes with that (i.e.,
flooding of LSAs, SPF runs). Helpful neighbors continue to forward packets
through the restarting router. The restarting router relearns the network
topology from its helpful neighbors.
PowerConnect implements both the restarting router and helpful neighbor
features described in RFC 3623.
Commands in this Chapter
This chapter explains the following commands:
capability opaque ip ospf priority
compatible rfc1583 ip ospf transmit-
2CSPC4.XModular-SWUM200.book Page 1068 Thursday, March 10, 2011 11:18 AM