==== 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 
        1002      269209056     2149.374  100.00% 
Conn:   1 Mbps:     2149.374 Peak Mbps:     2149.374 Avg Mbps:     2149.374
        2002      262572864     2100.583  100.00% 
Conn:   1 Mbps:     2100.583 Peak Mbps:     2149.374 Avg Mbps:     2100.583
        3003      280756224     2246.050  100.00% 
Conn:   1 Mbps:     2246.050 Peak Mbps:     2246.050 Avg Mbps:     2246.050
        4003      279266928     2234.135  100.00% 
Conn:   1 Mbps:     2234.135 Peak Mbps:     2246.050 Avg Mbps:     2234.135
        5003      274423568     2195.389  100.00% 
Conn:   1 Mbps:     2195.389 Peak Mbps:     2246.050 Avg Mbps:     2195.389
--- fc00:0:0:1::20 tcpbench statistics ---
1632566944 bytes sent over 6.000 seconds
bandwidth min/avg/max/std-dev = 2100.583/2185.106/2246.050/54.120 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
      25     32768         0 
DISABLED