Junos OSPF Configuration Generator

Generate a reviewed Junos OSPF area, interface and passive-interface configuration in set format.

Config generator Juniper / Junos Runs in your browser

Result

Area
0.0.0.0
Interfaces
3
Passive
1
Junos set commands
set routing-options router-id 10.255.0.1
set protocols ospf reference-bandwidth 100g
set protocols ospf area 0.0.0.0 interface ge-0/0/0.0
set protocols ospf area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf area 0.0.0.0 interface lo0.0
set protocols ospf area 0.0.0.0 interface lo0.0 passive
Verification commands
show ospf neighbor
show ospf interface detail
show route protocol ospf
show ospf database summary
Review authentication, interface type, export policy and BFD requirements before commit. Do not make transit links passive.

About Junos OSPF Configuration Generator

Build a minimal Junos OSPF configuration with explicit area membership and passive-interface handling. The output uses set format so it is easy to review, compare and paste into a candidate configuration.

Safe OSPF rollout

Start with the router ID and interface inventory, keep loopbacks passive, and verify every expected adjacency before relying on learned routes. Reference bandwidth should reflect the fastest meaningful path in the network so interface costs remain useful.

Design checks

Confirm area boundaries, interface network type, MTU, timers and authentication with the adjacent router. Inconsistent values can prevent adjacency or create routes with unexpected preference. Add BFD only when both ends and the operational team are prepared for its failure sensitivity. Before commit, compare the candidate and confirm that no existing protocol hierarchy will be replaced or deactivated by the change.

Common use cases

  • Configure a new routed link in an existing OSPF area.
  • Standardise branch or point-of-presence OSPF templates.
  • Prepare a reviewed candidate configuration for a maintenance window.

Edge cases and gotchas

  • Commit-check and review the candidate configuration before commit.
  • OSPF authentication is deployment-specific and is not generated.
  • After commit, verify neighbor state, database consistency, route counts, next hops and convergence. Keep commit confirmed or an equivalent rollback safeguard active until both control-plane and forwarding checks pass.

Frequently asked questions

Why is lo0.0 passive by default?
The loopback should be advertised but must not attempt to form an adjacency, so passive is the safe default. This keeps a stable reachable router address in OSPF without sending unnecessary hello packets or accepting an unexpected neighbor on that interface.
Does the generator configure authentication?
No. Authentication keys and algorithms are operational secrets and must follow the site security standard. Configure matching values securely on both neighbors.