Ensure you have kernel optimization tunes as the following disabled
sysctl -a |grep net.ipv4.tcp_tw_
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
To temporary disable without reboot:
sysctl -w net.ipv4.tcp_tw_recycle=0 sysctl -w net.ipv4.tcp_tw_reuse=0