RSTP Root Protect
Description
The Root Guard Notification occurs when the RSTP Profile’s "Root Protect Notification" is enabled, and a port receives an incoming RSTP BPDU which would result in that downstream port becoming the root of the STP topology. The BPDU will be discarded, and the port will be disabled for the duration of the NAC Profile’s "Auto Enable Delay". The alarm will clear after the Auto Enable Delay has expired, and the port will be re-enabled.
In most network architectures, the ONT ports should be attached to servers, end stations or devices. If a node below the ONT attempts to become the root of the tree, typically this indicates a misconfiguration or misconnection of the network. Typically, the OLT uplinks are attached to the core side of the network and the ONTs to end stations. In that configuration, it would almost always be a mistake for the root of the spanning tree to be off of an ONT port. In most cases, all traffic on the OLT would end up being sent through that ONT port. The BPDU Root Protect Notification will prevent the device attached to the ONT from becoming the root of the tree and distorting the normal functioning of the spanning tree. One other way that this can occur is misconfiguration of spanning tree attributes on a device below the ONT.
Root Protect Notification is configured in the RSTP profile. The RSTP profile is found in the Profiles 
icon->RSTP Tab>Edit 
icon->Edit Ethernet Port RSTP Profile.
icon->RSTP Tab>Edit icon->Edit Ethernet Port RSTP Profile.
The root protect notification, if enabled, will cause the Access Violation alarm to be sent with an Additional Text field indicating <Root Protect>. The BPDU will be discarded, and the port disabled for the duration of the NAC Profile’s Auto-Enable Delay timeout.
Trouble Clearing
To clear the alarm:
- Locate and remove the misconfiguration or misconnection to the network
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