Hi, We have to be PCI-DSS compliant and have several Windows servers running ISA and TMG. We have: Win 2K with ISA 2000 (on it's way out) Win 2K3 with ISA 2006 Win 2K8 R2 with TMG 2010 All of these servers, in the registry have TCP1323Opts set to '0' as per http://technet.microsoft.com/en-us/library/cc938205.aspx to disable TCP Timestamps. This is confirmed using Netsh where RFC 1323 Timestamps : disabled However, for PCI-DSS compliance we have to run vulnerability scans. Although only informational, all these servers come back as giving Timestamp replies. Although vulnerabilities due to this are minimal, from the timestamp is can be calculated how long a server has been running and therefore you can work out if it is missing the latest patches due to a lack of a reboot. I'm mainly puzzled as to why this is showing up when it is meant to be disabled. I've searched high and low across the Internet and can't find anything apart from the instructions as to how to change that reg entry. Do I need to do anything extra for the driver or something? Any help appreciated, Adrian

Hi, Thanks for the post. Please check if you add the Tcp1323Opts registry key as follows: Tcp1323Opts Key: Tcpip\Parameters Value Type: REG_DWORD—number (flags) Valid Range: 0 or 2 0 (disable the use of the TCP timestamps option) 2 (enable the use of the TCP timestamps option) Default: No value. Description: This value controls the use of the RFC 1323 TCP Timestamp option. The default behavior of the TCP/IP stack is to not use the Timestamp options when initiating TCP connections, but use them if the TCP peer that is initiating communication includes them in their synchronize (SYN) segment. For more information about TCP/IP Registry Values, you could access this link: http://download.microsoft.com/download/c/2/6/c26893a6-46c7-4b5c-b287-830216597340/tcpip_reg.doc Hope this helps. MilesPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Sorry about the late reply, I've been on holiday. Unfortunately I've got the Tcp1323Opts option set to 0 but the PCI-DSS vulnerability tests we have done still show timestamps. I'm stumped...

Any progress on this issue? I am seeing the same results with the registry entry set to 0 and netsh results show it as disabled but the PCI scan is showing it enabled. Any insight would be appreciated.

Sounds stupid, but verify/set the Tcp1323Opts=0 in CurrentControlSet001, 002, etc as well. I've seen weird stuff like that before

Sorry to jump on someone else's thread but i'm also having this issue. I've verified Tcp1323Opts=0 is set in all CurrentControlSets correctly, and using netsh it's showing as disabled but our PCI scans are still reporting it's enabled (as are our Nessus scans). Any information anyone can give would be very helpful Thanks

This answer does not seem adequate when several of us have the same issue and still have a flag reported by the PCI compliance scan. Someone suggested setting the parameters in the other control sets (beyond current control set). No one has mentioned also setting the parameters for IPv6, does it matter? I have added it to all these places and will let you know the result of my next scan.

Failed again... any other registry settings we need to change related to this?

I'm having this same issue. Any updates on this thread?

We never succeeded with an automated PCI compliance scan even after making all the suggested changes by the vendor and Microsoft. We finally got resolution by contacting the vendor running the scan for us and making a manual exception to override the results and we passed. So I can only suggest you do the same and hopefully your compliance vendor will give you approval.