Operation Manual – MSTP
H3C S3610&S5510 Series Ethernet Switches
Chapter 1 MSTP Configuration
1-45
Root port
Designated port
Root port blocks other
non-edge ports , changes
to forwarding state and
sends Agreement to
upstream switch
Downstream switch
Upstream Switch
Proposal for rapid transition
Designated port
changes to
forwarding state
Agre
eme
nt
Figure 1-10
Rapid state transition of an RSTP designated port
If the upstream device comes from another vendor, the rapid state transition
implementation may be limited. For example, when the upstream device adopts RSTP,
the downstream device adopts MSTP and does not support RSTP mode, the root port
on the downstream device receives no agreement packet from the upstream device
and thus sends no agreement packets to the upstream device. As a result, the
designated port of the upstream switch fails to transit rapidly and can only change to the
forwarding state after a period twice the Forward Delay.
In this case, you can enable the No Agreement Check feature on the downstream
device’s port to perform rapid state transition.
1.8.1 Configuration Prerequisites
z
A device is the upstream one that is connected to another vendor’s MSTP
supported device via a point-to-point link.
z
Configure the same region name, revision level and VLAN-to-instance mappings
on the two devices, making them in the same region.
1.8.2 Configuration Procedure
Follow these steps to configure No Agreement Check:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter
Ethernet
interface
view
interface
interface-type
interface-number
Enter
Ethernet
interface or
port group
view
Enter port
group view
port-group
{
manual
port-group-name |
aggregation
agg-id
}
Required
Use either command.
Configurations made in
Ethernet interface view
will take effect on the
current port only;
configurations made in
port group view will take
effect on all ports in the
port group.
