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RE: [Tool] HardTCP "Hardening TCP/IP" + SOURCE
From: DWreck <dwr3ckmailbox-fulldisclosure () yahoo com>
Date: Mon, 19 Jul 2004 07:45:20 -0700 (PDT)

Need to be careful when hardening the stack:
 

DefVal(8).Text = GetDWORDValue("HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters", 
"EnablePmtuDiscovery")
If DefVal(8).Text = "Error" Then DefVal(8).Text = "NP"
 
Disabling PMTU discovery sets the default MTU to 576 for all foreign networks.  In a properly segmented environment 
this setting can cause 3X the amount of packets sent between VLANs.


DefVal(11).Text = GetDWORDValue("HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters", 
"PerformRouterDiscovery")
If DefVal(11).Text = "Error" Then DefVal(11).Text = "NP"


Note:  Make sure IDRP is not in use in the clientÂ’s perimeter network.

Also, since the interface name changes whenever NICs are added/removed, keeping this edit in can be rough in large 
environments.

As for the rest, I've had 0 issues with the settings when implementing across 2000+ servers.



Thanks,

DWreck

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  • RE: [Tool] HardTCP "Hardening TCP/IP" + SOURCE DWreck (Jul 19)
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