Comment 1 for bug 1688121

With the fix applied, we get this:

$ time kinit -k -t /home/ubuntu/ubuntu.keytab ubuntu
real 0m0.023s

And the traffic happens all in UDP, since kinit got the "PREAUTH required" response (because now it came from the correct source IP) and just issued the updated request right away:
    1 0.000000000 10.0.5.55 → 10.0.5.155 KRB5 216 AS-REQ
    2 0.002060386 10.0.5.155 → 10.0.5.55 KRB5 298 KRB Error: KRB5KDC_ERR_PREAUTH_REQUIRED
    3 0.005412046 10.0.5.55 → 10.0.5.155 KRB5 311 AS-REQ
    4 0.012516720 10.0.5.155 → 10.0.5.55 KRB5 793 AS-REP