Dell N3200-ON EMC Networking N-Series Switches CLI Reference Guide version 6.7 - Page 1719

Passive Interfaces The passive interface feature is used to disable sending OSPF routing updates on an interface. An OSPF adjacency will not be formed on such an interface. On a passive interface, subnet prefixes for IP addresses configured on the interface will continue to be advertised as stub networks. 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. area default-cost (Router OSPF) Use the area default-cost command in Router OSPF Configuration mode to configure the advertised default cost for the stub area. Use the no form of the command to return the cost to the default value. Syntax area area-id default-cost integer no area area-id default-cost • area-id - Identifies the OSPF stub area to configure. (Range: IP address or decimal from 0-4294967295) • integer - The default cost for the stub area. (Range: 1-16777215) Layer 3 Routing Commands 1719