The managed device will refuse a request to set
pagpEthcOperationMode to the pagpOn(3) state if the device does
not implement the PAgP protocol. The managed device will refuse
to set pagpEthcOperationMode to manual(2) or pagpOn(3) if the
values in the interface's pagpAdminGroupCapability variable is
inconsistent with other interfaces' pagpAdminGroupCapability
values.