Router Mode

This chapter summarizes Open Shortest Path First (OSPF) router mode commands in the CLI command structure. All router-mode commands are available on both device and profile modes.

OSPF is an interior gateway protocol (IGMP) used within large autonomous systems to distribute routing information. OSPF routes IP packets within a single routing domain (autonomous system), like an enterprise LAN. OSPF gathers link state information from neighbor routers and constructs a network topology. The topology determines the routing table presented to the Internet Layer, which makes routing decisions based solely on the destination IP address found in IP packets.

OSPF detects changes in the topology, like a link failure, and plots a new loop-free routing structure. It computes the shortest path for each route using a shortest path first algorithm. Link state data is maintained on each router and is periodically updated on all OSPF member routers. This enables routers to synchronize routing tables.

OSPF uses a route table managed by the link cost (external metrics) defined for each routing interface. The cost could be the distance of a router (round-trip time), link throughput or link availability.

Use the (config) instance to configure router commands. To navigate to the (config-router-mode) instance, use the following command:

<DEVICE>(config-profile-<PROFILE-NAME>)#router ospf

nx9500-6C8809(config-profile-default-ap8533)#router ospf
nx9500-6C8809(config-profile default-ap8533-router-ospf)#

nx9500-6C8809(config-profile default-ap8533-router-ospf)#?
Router OSPF Mode commands:
  area                 OSPF area
  auto-cost            OSPF auto-cost
  default-information  Distribution of default information
  ip                   Internet Protocol (IP)
  network              OSPF network
  no                   Negate a command or set its defaults
  ospf                 OSPF
  passive              Make OSPF Interface as passive
  redistribute         Route types redistributed by OSPF
  route-limit          Limit for number of routes handled OSPF process
  router-id            Router ID

  clrscr               Clears the display screen
  commit               Commit all changes made in this session
  do                   Run commands from Exec mode
  end                  End current mode and change to EXEC mode
  exit                 End current mode and down to previous mode
  help                 Description of the interactive help system
  revert               Revert changes
  service              Service Commands
  show                 Show running system information
  write                Write running configuration to memory or terminal

nx9500-6C8809(config-profile default-ap8533-router-ospf)#