event 4226 TCP/IP has reached the security limit imposed on the number of concurrent TCP connect attempts RRS feed

  • Question

  • Hi,

    Our vpn users are getting this event along with other unpredictable behavior; print jobs disappearing, messages saying they don't have permission to do something (like send an e-mail or open a file share) when they do, general slow performance.

    There is apparently a limit on these connections (http://technet.microsoft.com/en-us/library/bb457156.aspx#EHAA) from XP SP2, and a slew of patches to tcpip.sys via third parties.  Microsoft fixed this on vista, win/7 and 2008 via sp2.

    My question is regarding XP SP3; is there a microsoft fix for this?

    We are using office communicator and remote desktop remote applications and these appear to max out the connections triggering the 4226 event, particularly when the client is using a VPN connection.

    Best regards,




    Sunday, October 16, 2011 2:06 PM

All replies

  • It is a built-in limitations of Windows XP set by the Service Pack 3.
    According to what I've read, you must follow the instructions in the Microsoft Knowledge Base article at the following web address


    to run the patch again.


    Luigi Bruno - Microsoft Community Contributor 2011 Award
    Sunday, October 16, 2011 3:59 PM
  • Thanks for the inputs Luigi, was able to connect into a client with psexec and run netstat -no to a file which indicated tcp connections were not actually the problem.

    This turned out to be a problem with the CheckPoint SecureClient software, checked the box to "Route all traffic through gateway" on the site properties and the clients now behave properly.


    Saturday, October 22, 2011 1:13 PM