Determining a path through a managed network

A computer readable medium having stored thereon instructions which when executed by one or more processors, cause the one or more processors to determine a route for a data packet from a source node to a destination node, said computer readable medium comprising:

• instructions for determining a first portion in the route by identifying a first gateway in the route, wherein the first portion is from the source node to the first gateway, wherein the first gateway is the next intermediate gateway that a packet send from the source node to the destination node would visit, and wherein the source node does not support source-route IP path tracing;
• and
• instructions for determining a second portion of the route by source-route IP path tracing, wherein the second portion is from the first gateway to the destination node,
• wherein identifying the first gateway comprises the steps of:
• determining a second gateway used by the source node to reach a network management node;
• determining a third gateway based on the second gateway and the destination node;
• using the second gateway as the first gateway only if the third gateway and the source node are on different subnets;
• and
• using the third gateway as the first gateway only if the third gateway and the source node are on the same subnets.

An apparatus for determining a route for a data packet from a source node to a destination node, comprising:

• means for determining a first portion in the route by identifying a first gateway in the route, wherein the first portion is from the source node to the first gateway, wherein the first gateway is the next intermediate gateway that a packet send from the source node to the destination node would visit, wherein the source node does not support source-route IP path tracing;
• and
• means for determining a second portion of the route by source-route IP path tracing, wherein the second portion is from the first gateway to the destination node,
• wherein the means for determining a first portion in the route by identifying a first gateway in the route comprises:
• means for determining a second gateway used by the source node to reach a network management node;
• means for determining a third gateway based on the second gateway and the destination node;
• means for using the second gateway as the first gateway only if the third gateway and the source node are on different subnets;
• and
• means for using the third gateway as the first gateway only if the third gateway and the source node are on the same subnets.

An apparatus for determining a route for a data packet from a source node to a destination node, comprising:

• a processor;
• a network interface that is communicatively coupled to the processor and to a network for sending and receiving packet flows on the network;
• and
• a computer-readable medium accessible to the processor and comprising one or more sequences of instructions which, when executed by the processor, cause the processor to perform the steps of:
• determining a first portion in the route by identifying a first gateway in the route, wherein the first portion is from the source node to the first gateway, wherein the first gateway is the next intermediate gateway that a packet send from the source node to the destination node would visit, wherein the source node does not support source-route IP path tracing;
• and
• determining a second portion of the route by source-route IP path tracing, wherein the second portion is from the first gateway to the destination node,
• wherein determining a first portion in the route by identifying a first gateway in the route comprises:
• determining a second gateway used by the source node to reach a network management node;
• determining a third gateway based on the second gateway and the destination node;
• using the second gateway as the first gateway only if the third gateway and the source node are on different subnets;
• and
• using the third gateway as the first gateway only if the third gateway and the source node are on the same subnets.