==== run-tcpbench6-3-1 ====
rm -f nc.log
nc -6 -v -l -V 20 fc00:0:0:1::20 12345 >/dev/null 2>nc.log &
# Wait until nc is listening.
for  i in `jot 30`; do if fgrep -q Listening nc.log; then break; fi; sleep .1; done
fgrep Listening nc.log
Listening on fc00:0:0:1::20 12345
# Test that path MTU dicovery is working.
tcpbench -6 -t 5 -V 22 -b fc00::22 fc00:0:0:1::20
  elapsed_ms          bytes         mbps   bwidth 
        1001      268718744     2147.602  100.00% 
Conn:   1 Mbps:     2147.602 Peak Mbps:     2147.602 Avg Mbps:     2147.602
        2001      265974264     2129.924  100.00% 
Conn:   1 Mbps:     2129.924 Peak Mbps:     2147.602 Avg Mbps:     2129.924
        3001      282446968     2261.838  100.00% 
Conn:   1 Mbps:     2261.838 Peak Mbps:     2261.838 Avg Mbps:     2261.838
        4002      270655056     2165.240  100.00% 
Conn:   1 Mbps:     2165.240 Peak Mbps:     2261.838 Avg Mbps:     2165.240
        5002      282645688     2261.166  100.00% 
Conn:   1 Mbps:     2261.166 Peak Mbps:     2261.838 Avg Mbps:     2261.166
--- fc00:0:0:1::20 tcpbench statistics ---
1650672656 bytes sent over 6.000 seconds
bandwidth min/avg/max/std-dev = 2129.924/2193.154/2261.838/56.912 Mbps
# path MTU discovery in other rtable does not work in ip6_output()
/sbin/route -T 22 -n get -host -inet6 fc00:0:0:1::20
   route to: fc00:0:0:1::20
destination: fc00::
       mask: ffff:ffff:ffff::
    gateway: ::1
  interface: lo22
 if address: ::1
   priority: 8 (static)
      flags: <UP,GATEWAY,DONE,STATIC>
     use       mtu    expire
      20     32768         0 
DISABLED