Forum Discussion

Hamza's avatar
Hamza
Icon for Cirrus rankCirrus
Jan 19, 2023

Impact of disabling TCP Timestamp in TCP and fasl4 profile

Hello, We have conduction a recent PCI scan which identified TCP timestamp as a risk. I would like to know the impact of disabling tcp timestamp in tcp and fastl4 profiles for clinet and sever side...
security
  • Paulius's avatar
    Paulius
    Jan 19, 2023

    Hamza from my understanding this would make it so if you were looking at a tcpdump you wouldn't be able to accurately record the round trip time for communication back and forth as well as anything that uses the timestamp to adjust the receive window or transmit buffer.

Gajji's avatar
Gajji
Icon for Cirrostratus rankCirrostratus
Jan 25, 2023

It have a few impacts on both the client and server side. 

1)it may affect the accuracy of RTT measurements, which can be used by TCP to adjust its congestion 

control algorithms. 

2)Another impact is that it can help in avoiding information leakage through the timestamp

 fields which could be used for tracking or fingerprinting the systems.