A computer-implemented method in a data communications network comprising a plurality of nodes and supporting multiple topologies, comprising: monitoring packets received from an internetworked system, wherein the packets are received on one or more of a plurality of network interfaces of a networking device; detecting that a received packet includes real-time information that signals a present or pending congestion condition on a path from the one or more network interfaces of the networking device to the internetworked system, the path being specified by policy-based routing for a class of packets based on an application or identified by a prefix associated with the internetworked system; wherein the present or pending congestion condition is experienced by a first traffic flow of packets on the path from the one or more network interfaces of the networking device to the internetworked system, the first flow of packets being associated with the application or identified by the prefix; notifying a control logic of the real-time information; receiving from the control logic control information defining a change in one or more paths from the one or more network interfaces of the networking device to the internetworked system; wherein the change is defined by the control logic, in response to the real-time information, to not change the path for the first traffic flow of packets associated with the prefix or application, but to divert other traffic flows associated with other prefixes or applications from the path to other paths that are better than the path; and changing the one or more paths from the one or more network interfaces of the networking device to the internetworked system. monitoring packets received from an internetworked system, wherein the packets are received on one or more of a plurality of network interfaces of a networking device; detecting that a received packet includes real-time information that signals a present or pending congestion condition on a path from the one or more network interfaces of the networking device to the internetworked system, the path being specified by policy-based routing for a class of packets based on an application or identified by a prefix associated with the internetworked system; wherein the present or pending congestion condition is experienced by a first traffic flow of packets on the path from the one or more network interfaces of the networking device to the internetworked system, the first flow of packets being associated with the application or identified by the prefix; notifying a control logic of the real-time information; receiving from the control logic control information defining a change in one or more paths from the one or more network interfaces of the networking device to the internetworked system; wherein the change is defined by the control logic, in response to the real-time information, to not change the path for the first traffic flow of packets associated with the prefix or application, but to divert other traffic flows associated with other prefixes or applications from the path to other paths that are better than the path; and changing the one or more paths from the one or more network interfaces of the networking device to the internetworked system.