Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

This is an IPv6-version of the following question:

Why Windows 7 / PuTTY drop TCP connections even on very brief outages?

After moving from IPv4 to IPv6, I've noticed that my IPv6 connections would drop all the time (e.g. overnight). I've now finally caught it dropping after only a couple of seconds when IPv6 connectivity was temporarily lost on the remote host.

It would appear that creating TcpMaxDataRetransmissions, with a value like 0x18 (24), within HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\TCPIP6\Parameters, has no effect in Windows 7 (unlike the corresponding IPv4 setting). Why?

How do I prevent the IPv6 TCP connections from dropping so quickly? My IPv4 connections remains active for minutes during the temporary periods of no connectivity, after creating the same value (and a reboot) within HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters, as per the referenced question.

share|improve this question
Do you have native IPv6 or a tunnel? From whom? – Michael Hampton Jan 16 '14 at 1:40
@MichaelHampton: Native IPv6 on the client end, with static IPv6 provisioning (IPv6 address, preflen and gateway are manually specified in the IPv6 Properties), with IPv4 done through DHCP. – cnst Jan 16 '14 at 3:06

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.