Techniques for determining a problem location or otherwise characterizing
a network comprising a plurality of processing elements, including at
least one processing element associated with performance of a packet
encapsulation operation of an encapsulation protocol. The packet
encapsulation operation is performed on a test packet to generate an
encapsulated packet, the test packet having a time to live (TTL) value
and an identifier. In conjunction with performance of the packet
encapsulation operation, the TTL value and the identifier of the test
packet are copied to a header of the encapsulated packet. The
encapsulated packet is transmitted, and a determination is made as to
whether a reply packet has been received responsive to transmission of
the encapsulated packet. The reply packet, if any, is processed to obtain
information utilizable in determining the problem location or otherwise
characterizing the network. By way of example, these operations may be
repeated, for subsequent test packets with increasing TTL values, until
an amount of router hop information sufficient to determine the problem
location is obtained.