Administrator Guide

Layer 3 Routing Commands 1652
Graceful Restart
The Dell EMC Networking implementation of OSPFv2 supports graceful
restart as specified in RFC 3623. Graceful restart works in concert with Dell
EMC Networking 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.
Dell EMC Networking implements both the restarting router and helpful
neighbor features described in RFC 3623.
Commands in this Section
This section explains the following commands:
area default-cost
(Router OSPF)
capability opaque ip ospf network show ip ospf area
area nssa (Router
OSPF)
clear ip ospf ip ospf priority show ip ospf asbr
area nssa default-
info-originate
(Router OSPF
Config)
clear ip ospf stub-
router
ip ospf retransmit-
interval
show ip ospf database
area nssa no-
redistribute
compatible rfc1583 ip ospf transmit-
delay
show ip ospf database
database-summary
area nssa no-
summary
default-information
originate (Router
OSPF
Configuration)
log adjacency-
changes
show ip ospf interface
area nssa translator-
role
default-metric max-metric router-
lsa
show ip ospf interface
brief