1. A method, comprising: selecting a plurality of segment identifiers, wherein said selecting comprises accessing a data structure relating each of the segment identifiers to one or more nodes within a network, and interior gateway protocol (IGP) advertisements are used to communicate the segment identifiers for creation or updating of the data structure; assembling the plurality of segment identifiers into a segment identifier stack, wherein the segment identifier stack encodes a test path within the network for attempted routing of a test message; inserting the segment identifier stack into a header associated with the test message; and forwarding the test message according to an entry in a forwarding table corresponding to a segment identifier at the top of the segment identifier stack, wherein IGP advertisements are used to communicate the segment identifier at the top of the segment identifier stack for creation or updating of the forwarding table.