Transparent Interconnection of Lots of Links (TRILL) is a protocol that provides optimal routing and forwarding for link-level frames. It uses a modification of IS-IS protocol for sharing link state information between TRILL enabled bridges, and a lightweight TRILL header for encapsulating and routing frames. This test suite can be used to test TRILL implementations for security flaws and robustness problems. The TRILL version of IS-IS implements extensions from a number of different specifications, including the core TRILL specifications. TRILL as a protocol is agnostic to the link layer technology, but the test suite currently supports IEEE 802.3 Ethernet transport as demonstrated in RFC6325. The test suite also supports 802.1Q VLAN tags.