4000 Router Series Layer 2 - LAN Switching Configuration Guide

device receives no agreement packet from the upstream device and sends no agreement packets to the

upstream device. As a result, the designated port of the upstream device fails to transit rapidly, and can

only change to the forwarding state after a period twice the Forward Delay.

You can enable the No Agreement Check feature on the downstream device's port to enable the

designated port of the upstream device to transit its state rapidly.

Configuration prerequisites

Before you configure the No Agreement Check function, complete the following tasks:

• Connect a device to a third-party upstream device that supports spanning tree protocols through a

point-to-point link.

• Configure the same region name, revision level and VLAN-to-instance mappings on the two devices,

assigning them to the same region.

Configuration procedure

Enable the No Agreement Check feature on the root port.

To configure No Agreement Check:

Step Command Remarks

1. Enter system view.

system-view N/A

2. Enter Layer 2 Ethernet

interface view.

interface interface-type interface-number N/A

3. Enable No Agreement

Check.

stp no-agreement-check

By default, No Agreement

Check is disabled.

No Agreement Check configuration example

Network requirements

As shown in Figure 11:

• Device A connects to a third-party device that has a different spanning tree implementation. Both

devices are in the same region.

• The third-party device (Device B) is the regional root bridge, and Device A is the downstream

device.

Figure 11 Network diagram