Helping traceroute

traceroute needs a bit of help, but uses a fixed formula:

# allow out the default range for traceroute(8):
# "base+nhops*nqueries-1" (33434+64*3-1)
pass out on $ext_if inet proto udp from any to any \
     port 33433 >< 33626 keep state

This is the stuff you find in list archives - openbsd-misc (e. g.

Note: Unix traceroute uses UDP by default; Microsoft uses ICMP ECHO (like unix with -I)