Comment 19 for bug 1817936

although curl command is invalid test case, but for python test code.
import urllib
import datetime
for i in range(1,20000):
    now = datetime.datetime.now()
    print("start %s at: %s" % (i,now))
    try:
        response = urllib.urlopen("http://glance-api.openstack.svc.cluster.local:9292")
        print(response.read())
        response.close()
    except:
        now = datetime.datetime.now()
        print("Error %s at: %s" % (i,now))
        exit()
    now = datetime.datetime.now()
    print("end %s at: %s" % (i,now))

This issue is still reproducible even local port range 49216-61000 or 45000-65500 or 32768-60999.
need more investigation.