# option on the SYN, but the fast-output SMTP banner will not
# be seen unless you also deliberately emulate a long path:
# 'sudo tc qdisc add dev lo root netem delay 50ms'
+# You'll need iproute-tc installed, for the tc command.
# You'll need kernel-modules-extra installed, or you get
# an unhelpful error from RTNETLINK.
# To tidy up: 'sudo tc qdisc delete dev lo root'