Recommended Posts

Hi Guys,

 

We have a problem with our environment. we have DHCP server configured with Public IP range in SCOPE hence our client machine (windows 7/8) received the same range of IP address. However in our DNS server we found there are IPv6 (Host AAAA) records has been created along with host A record for any individual system. 

 

when we ping to any system it will give as RTO because it's got response from IPv6.

 

We have unchecked the IPv6 option from NIC properties. 

 

As per the MS article,  https://support.microsoft.com/en-us/kb/929852

 

About the 6to4 tunneling protocol

By default, the 6to4 tunneling protocol is enabled in Windows 7, Windows Vista, Windows Server 2008 R2, and Windows Server 2008 when an interface is assigned a public IPv4 address (that is, an IPv4 address that is not in the ranges 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16). 6to4 automatically assigns an IPv6 address to the 6to4 tunneling interface for each such address that is assigned, and 6to4 will dynamically register these IPv6 addresses on the assigned DNS server. If this behavior is not desired, we recommend that you disable IPv6 tunnel interfaces on the affected hosts.

As we used same range of DHCP scope (Public IP range) since last 3 years but such issue is just occurs recently... Anyone faced such issue? please assist me on this case.

 

Thanks in advance. 

Link to comment
https://www.neowin.net/forum/topic/1252322-ping-not-working-correctly/
Share on other sites

If you are not ready to use IPv6, I really would suggest you disable it completely..

 

http://support.microsoft.com/en-us/kb/929852

 

This can be done via group policy you might want to look here

http://social.technet.microsoft.com/wiki/contents/articles/5927.how-to-disable-ipv6-through-group-policy.aspx

 

What does your ipconfig /all look like on a windows machine?  Out of the box your going to get link-local addresses on the interface.  Out of the box all addresses on this interface will be registered via dns in AD, etc. Out of the box ipv6 would be used first if you get a response for AAAA dns query.

 

Again highly recommend if your not ready to use ipv6 in your network, that you just completely disable it. This is a simple enough to turn on and turn off.

 

If you see any ipv6 stuff on your interface in ipconfig /all then yeah its most likely going to to get registered in DNS that can cause you grief if not actively setup to actually use ipv6.  Also all those nonsense transition to ipv6 interfaces like teredo, 6to4 and isatap should also just be disable and removed.. Unless you were actively wanting to use 1.. And then that 1 should be setup and the others turned off.  See the kb article linked too.

 

Ipv6 is coming, but unless your up to speed on it - it causes problems!! For example the one your seeing - it also causes noise that just serves no purpose on the network unless actively using ipv6.  Also after cleanup your ipconfig /all will be much cleaner ;)

 

I don't ever have any of the teredo, isatap, 6to4 stuff since I have cleaned that up - but I do have ipv6 configured and can enable or disable it with the checkbox in the network interface props.  So you see the top ipconfig /all when I have it disabled.  When I enable it I have both a global ipv6 address, the one that starts with 2001, and then the link local address the fe80 address.

post-14624-0-42856200-1428078883.png

 

Simple way to explain link local is think of them of private IPs (rfc1918) that are not routable on the public internet, 192.168.1.0/24 for example.  While if its a global ipv6 address then its public IP.  link locals can and are used on your local network.  But as stated, you really don't want those registered in your AD dns unless unless your network is really ready for use of ipv6 on a global setup.

ipconfig /all:

 

   Description . . . . . . . . . . . : Intel® 82579LM Gigabit Network Connection
 
   Physical Address. . . . . . . . . : 14-58-xx-xx-xx-xx
 
   DHCP Enabled. . . . . . . . . . . : Yes
 
   Autoconfiguration Enabled . . . . : Yes
 
   Link-local IPv6 Address . . . . . : fe80::xxxxx:xx:xx:%11(Preferred)
 
   IPv4 Address. . . . . . . . . . . : 161.xx.xx.x4(Preferred)
 
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
 
   Lease Obtained. . . . . . . . . . : Monday, March 28, 2015 8:53:52 AM
 
   Lease Expires . . . . . . . . . . : Tuesday, April 03, 2015 8:53:53 AM
 
   Default Gateway . . . . . . . . . : 161.xx.xx.xx
 
   DHCP Server . . . . . . . . . . . : 10.xx.xx.136
 
   DHCPv6 IAID . . . . . . . . . . . : 29887
 
   DHCPv6 Client DUID. . . . . . . . : 00-01-90-01-1S-87-O8-FD-14-28-D0-BA-7H-61
 
 
 
   DNS Servers . . . . . . . . . . . : 10.xx.xx.131
 
   NetBIOS over Tcpip. . . . . . . . : Enabled
 
 
 
Tunnel adapter 6TO4 Adapter:
 
 
 
   Connection-specific DNS Suffix  . :
 
   Description . . . . . . . . . . . : Microsoft 6to4 Adapter #2
 
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
 
   DHCP Enabled. . . . . . . . . . . : No
 
   Autoconfiguration Enabled . . . . : Yes
 
   IPv6 Address. . . . . . . . . . . : 2002:a1fp:d6a::a1fp:d7a(Preferred)
 
   Default Gateway . . . . . . . . . :
 
   DNS Servers . . . . . . . . . . . : 10.xx.xx.131
 
 
   NetBIOS over Tcpip. . . . . . . . : Disabled

And have you disabled ipv6??  Your 6to4 has address

 

2002:a1fp:d6a::a1fp:d7a(Preferred)

 

Pretty sure its going to try and register than.. Do a query for that computer name against your dns.. Do you get back ipv6 in a AAAA ?  When a computer has  public IPv6, that 6to4 will be used and will try will register in AD..

 

Here this is perfect article that goes over your issue with that 6to4

 

http://blogs.technet.com/b/askpfeplat/archive/2013/11/18/ipv6-for-the-windows-administrator-the-2002-6to4-tunnel-address-and-its-impact.aspx

 

Again if you are not ready to use ipv6 on your network, the cleanest approach is just disable it completely, remove all the adapters isatap, 6to4, teredo - you have no need for those - do you??  If you did you would have properly set the one you wanted to use up and disable the others you would of thunk ;)

 

Your other option so that 6to4 does not create address is no use public IP space on an internal network.

Thanks Budman, Issue is now resolved, we created GPO were configured IPv4 preference order over the IPv6. 

 

reference URL as you shared in your previous post.

http://social.technet.microsoft.com/wiki/contents/articles/5927.how-to-disable-ipv6-through-group-policy.aspx

 

Thanks :) 

  On 22/04/2015 at 12:51, BudMan said:

no you didn't remove the crap  Why?

Cause, system start pining to destination with IPv4, So issue just resolved that's why we didn't remove any thing. from few system we just disabled the 6to4 adopter from device manager.

 

Will remove the rest system in any weekend now. Thanks for your help Budman...  I really appreciate.  :)

  • 1 month later...

"just disabled the 6to4 adopter from device manager."

 

Not really proper way to disable it, done with a simple netsh cmd

netsh interface ipv6 6to4 set state disabled

Or can be disabled with proper flags in disabledcomponents for ipv6

 

https://support.microsoft.com/en-us/kb/929852

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • Quantum computer does something for first time, creates "certified truly random" numbers by Sayan Sen Image by Ron Lach via Pexels A group of researchers from JPMorganChase, Quantinuum, Argonne National Laboratory, Oak Ridge National Laboratory, and The University of Texas at Austin has reached a major milestone in quantum computing. In a new paper published in Nature, they describe how they used a 56-qubit quantum computer to generate random numbers and then proved those numbers were truly random using powerful classical supercomputers. This achievement, called "certified randomness," could be useful in areas like cryptography, privacy, and fairness. Certified randomness means the numbers are not just unpredictable, but also freshly created and mathematically verified. Classical computers can’t do this on their own. They usually rely on hardware random-number generators, which can be tampered with. But with this new method, even if someone tried to interfere with the quantum computer, they wouldn’t be able to fake the randomness and still pass the certification. The idea behind the protocol was first proposed by Scott Aaronson, a computer science professor at UT Austin. He worked with his former postdoctoral researcher, Shih-Han Hung, to support the experimental team. “When I first proposed my certified randomness protocol in 2018, I had no idea how long I’d need to wait to see an experimental demonstration of it,” Aaronson said. “Building upon the original protocol and realizing it is a first step toward using quantum computers to generate certified random bits for actual cryptographic applications.” To carry out the experiment, the team accessed Quantinuum’s System Model H2-1 quantum computer over the internet. They used a method called random circuit sampling (RCS), which is known to be extremely hard for classical computers to simulate. The process had two main steps. First, the researchers sent the quantum computer a series of challenge circuits created from a small seed of randomness. The quantum computer had to solve these challenges by picking one of many possible answers at random. Then, in the second step, classical supercomputers checked the results to confirm the randomness was real. The team used several supercomputers with a combined performance of 1.1 × 10¹⁸ floating-point operations per second (1.1 ExaFLOPS) to certify 71,313 bits of entropy. This means they proved that the random bits couldn’t have been generated by classical methods, at least not under realistic conditions and assumptions. “This work marks a major milestone in quantum computing, demonstrating a solution to a real-world challenge using a quantum computer beyond the capabilities of classical supercomputers today,” said Marco Pistoia, Head of Global Technology Applied Research at JPMorganChase. Quantinuum had upgraded its H2 system to 56 qubits in June 2024. Thanks to its high accuracy and ability for any qubit to connect with any other, the system was able to perform RCS far better than previous machines. This upgrade, combined with Aaronson’s protocol, made the breakthrough possible. “Today, we celebrate a pivotal milestone that brings quantum computing firmly into the realm of practical, real-world applications,” said Dr. Rajeeb Hazra, President and CEO of Quantinuum. “These results in quantum computing were enabled by the world-leading U.S. Department of Energy computing facilities at Oak Ridge National Laboratory, Argonne National Laboratory and Lawrence Berkeley National Laboratory,” said Travis Humble, director of the Quantum Computing User Program at ORNL. While quantum computers have shown they can outperform classical ones in theory, turning that power into something useful has been a challenge. This experiment shows that quantum computers can now do something practical that classical computers simply can’t match. Source: University of Texas, Nature This article was generated with some help from AI and reviewed by an editor. Under Section 107 of the Copyright Act 1976, this material is used for the purpose of news reporting. Fair use is a use permitted by copyright statute that might otherwise be infringing.
    • I noticed when I click on the update button (from the desktop app), it says I'm still on the latest version, that does not give me access to ChatGPT five, and I do not see GPT-5 even in the web account either, despite being a pro customer.
    • That heavily compressed and pixelated image IS NOT THE HIGH RESOLUTION wallpaper! It looks like absolute trash due to the excessive pixelation from the multiple rounds of compression on it. Like, seriously, on my 10-yr-old PC it doesn't take more than a simple image viewer to see that this is not a high-res image to begin with! EDIT: The non-Reddit compressed version is available on a CDN at https://cdn.mos.cms.futurecdn.net/Vt84y2Lg4Pgpkkqk7VMLLa.jpg
  • Recent Achievements

    • First Post
      EzraNougat earned a badge
      First Post
    • One Month Later
      westDvina earned a badge
      One Month Later
    • Community Regular
      Bern@rd went up a rank
      Community Regular
    • Week One Done
      Joey Solo earned a badge
      Week One Done
    • Week One Done
      Vicente C Alves earned a badge
      Week One Done
  • Popular Contributors

    1. 1
      +primortal
      711
    2. 2
      +FloatingFatMan
      202
    3. 3
      ATLien_0
      163
    4. 4
      Xenon
      130
    5. 5
      wakjak
      110
  • Tell a friend

    Love Neowin? Tell a friend!