A method comprising: encapsulating an inner packet , the inner packet being configured with a multicast address and being configured to perform a traceroute operation through a network, to form an encapsulated packet ; sending the encapsulated packet into the network, the encapsulated packet being forwarded along a multicast tree of the network for the multicast address from a source device to a plurality of destination devices ; and receiving a response message from each of a plurality of network nodes comprising the multicast tree between the source device and each of the plurality of destination devices , wherein each response message comprises an indication of a node of the plurality of network nodes that sends the response message and an indication of a network node from which the node sending the response message received the encapsulated packet, and further comprising: modifying header information of the inner packet to form a modified inner packet; encapsulating the modified inner packet to form a modified encapsulated packet; sending the modified encapsulated packet into the network , wherein the modified encapsulated packet is forwarded along a second multicast tree of the network for the multicast address in response to the modifying; and receiving responses from a plurality of network nodes comprising the second multicast tree, wherein the multicast tree and the second multicast tree are load balanced multicast forwarding trees. encapsulating an inner packet , the inner packet being configured with a multicast address and being configured to perform a traceroute operation through a network, to form an encapsulated packet ; sending the encapsulated packet into the network, the encapsulated packet being forwarded along a multicast tree of the network for the multicast address from a source device to a plurality of destination devices ; and receiving a response message from each of a plurality of network nodes comprising the multicast tree between the source device and each of the plurality of destination devices , wherein each response message comprises an indication of a node of the plurality of network nodes that sends the response message and an indication of a network node from which the node sending the response message received the encapsulated packet, and further comprising: modifying header information of the inner packet to form a modified inner packet; encapsulating the modified inner packet to form a modified encapsulated packet; sending the modified encapsulated packet into the network , wherein the modified encapsulated packet is forwarded along a second multicast tree of the network for the multicast address in response to the modifying; and receiving responses from a plurality of network nodes comprising the second multicast tree, modifying header information of the inner packet to form a modified inner packet; encapsulating the modified inner packet to form a modified encapsulated packet; sending the modified encapsulated packet into the network , wherein the modified encapsulated packet is forwarded along a second multicast tree of the network for the multicast address in response to the modifying; and receiving responses from a plurality of network nodes comprising the second multicast tree, wherein the multicast tree and the second multicast tree are load balanced multicast forwarding trees. <EOS>