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.