Increasing DefaultTTL in Registry Has No Effect

• Microsoft Windows NT Workstation version 3.5
• Microsoft Windows NT Server version 3.5

SYMPTOMS

By default, the DefaultTTL setting in the Windows NT registry under HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES\TCPIP\PARAMETERS is 32 decimal. If this value is changed to anything above 32, the Default Time to Live value is unaffected. Packets will not reach a remote destination.

If you have a destination that Tracert shows is 41 hops away and the default TTL is 32, packets will not reach the destination. If you change the default TTL on the ping command line to 45, by using the -i switch, the packets will make it to the destination.

This problem occurs only with the PING utility because it is hard coded to use 32 for the TTL. Other utilities, like Telnet and FTP, use the correct registry TTL value. For Ping utility, "-i" switch can be used to specify a different TTL.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: prodnt

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