ptb6: conn [::1].1308 <-> [::1].49172
before-PTB : t_state=5 t_maxseg=14336 t_maxopd=16324 t_rttupdated=11 snd_ssthresh=28672 snd_cwnd=28676
ptb6: injected ICMPv6 PTB mtu=1300 quoting ::1.1308 -> ::1.49172
after-PTB  : t_state=5 t_maxseg=1240 t_maxopd=1240 t_rttupdated=11 snd_ssthresh=28672 snd_cwnd=28676
ptb6: -x given; sleeping so you can inspect