ospf smart-discover

Function

The ospf smart-discover command enables smart-discover on an interface.

The undo ospf smart-discover command disables smart-discover from an interface.

By default, smart-discover is disabled on interfaces.

Format

ospf smart-discover

undo ospf smart-discover

Parameters

None

Views

100GE interface view, 10GE interface view, 25GE sub-interface view, 25GE interface view, 400GE interface view, 40GE interface view, 50GE sub-interface view, 50GE interface view, Eth-Trunk interface view, FlexE interface view, GE optical interface view, GE electrical interface view, GMPLS-UNI interface view, Global VE sub-interface view, Tunnel interface view, VBDIF interface view, VE sub-interface view, VLANIF interface view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
ospf	write

Usage Guidelines

Usage Scenario

In most cases, devices periodically send Hello packets through OSPF interfaces. By sending Hello packets, devices set up and maintain neighbor relationships, and elect the DR and BDR on the multi-access network (broadcast or NBMA network). When setting up neighbor relationships or electing the DR and BDR on the multi-access network, interfaces can send Hello packets only when the Hello timer expires. This slows down the establishment of neighbor relationships and election of the DR and BDR.

After smart-discover is configured, when the status of the neighbor relationship changes or the DR and BDR on the multi-access network changes, the device can send Hello packets to its neighbor immediately without waiting for the Hello timer to expire.

Procedure

On broadcast and NBMA networks, neighbor relationships can be rapidly set up and a DR and a BDR can be rapidly elected.

When the neighbor status becomes 2-way for the first time or returns to Init from the 2-way or higher state, the smart-discover-enabled interface sends Hello packets to a neighbor without waiting for the Hello timer to expire when detecting that the neighbor status changes.
When the status of the interface functioning as the DR or BDR on the multi-access network changes, the smart-discover-enabled interface sends unsolicited Hello packets on the network segment and then runs for the DR or BDR.
The principle of setting up adjacencies rapidly on P2P or P2MP networks is the same as that on broadcast and NBMA networks.

Implementation Procedure

On broadcast and NBMA networks, neighbor relationships can be rapidly set up and a DR and a BDR can be rapidly elected.

When the neighbor status becomes 2-way for the first time or returns to Init from the 2-way or higher state, the smart-discover-enabled interface sends Hello packets to a neighbor without waiting for the Hello timer to expire when detecting that the neighbor status changes.
When the status of the interface functioning as the DR or BDR on the multi-access network changes, the smart-discover-enabled interface sends unsolicited Hello packets on the network segment and then runs for the DR or BDR.
The principle of setting up adjacencies rapidly on P2P or P2MP networks is the same as that on broadcast and NBMA networks.

Configuration Impact

The interval at which Hello packets are sent by an interface is determined by the configured interval on the interface.

Precautions

The default interval at which Hello packets are sent varies with the network type.

Example

# Enable smart-discover.

<HUAWEI> system-view
[~HUAWEI] interface GigabitEthernet0/1/0
[~HUAWEI-GigabitEthernet0/1/0] ospf smart-discover