Please register which TCP ports your tests are using in this file so
others don't accidentally conflict.

6000 - DrDr X11 server
....
6100 - DrDr X11 server
8887 - tests/racket/benchmarks/shootout/echo
8888 - tests/racket/benchmarks/shootout/typed/echo (non-optimized)
8889 - tests/racket/benchmarks/shootout/typed/echo (optimized)
9000 - DrDr Web server
9001 - tests/net
9999 - tests/web-server
