IPv6 addresses being returned

Hi All,

For some reason my system now returns IPv6 addreses when I ping or tracert a machine on my network, my coldfusion apps #CGI.remote_Addr# returns the v6 address. Other than stay current with my M$ security patches I've not done anything that I can recall to give IPV6 preference.

How do I return things to an IPv4 state such that a ping will return the IPv4 address not the IPv6 address, and coldfusion apps will show the IPv4 address without having to add -4 to the cmd (which I can't do in my CF apps).

I recently built a new Win 7 machine which replaces an XP machine. This machine is used as a server, runs coldfusion, firebird and a few other things. on that machine, pinging machines on my network returns IPv4 addresses, but on all other machines they return IPv6.

thanks
Tanya

Tanyam said:

Hi All,

For some reason my system now returns IPv6 addreses when I ping or tracert a machine on my network, my coldfusion apps #CGI.remote_Addr# returns the v6 address. Other than stay current with my M$ security patches I've not done anything that I can recall to give IPV6 preference.
thanks
Tanya

Silly question, huh?

I found that by plugging in an XP machine into my network ping from all machines subsequently returns the IPv4 address. Whereas, when there are only Windows 7 machines on the network IPv6 addresses are always returned.

How many humans can remember 20 IPv6 addresses off the top of their head? Not many. Certainly not me, so it looks like I'm going to have to leave the XP machine connected to the network.

There seems to be no environment variable to force ping to return the IPv4 address, and no coldfusion variable either. I'll have to create a lookup table to do the latter.

Doesn't explain why the Windows 7 server returned the IPv4 address, when all others returned IPv6 addresses, though.

Well, this seems to get me back to seeing the IPv4 addresses...
(Except when pinging my own machine which returns the IPv6 loopback address ::1)

start-->run-->regedit
Navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters
Create a new 32bit Dword (this works for both x86 and x64 machines) and call it "DisabledComponents"
Right-click and select modify. Fill in the field with all f's.
Reboot.
When you look at the properties of your network connection in "Network and Sharing Center" tcp/ipv6 will still show up with a check mark looking like its working, but it's not.
You can verify by opening a command prompt as administrator and typing "ipconfig /all" you will see there are no longer any tcp/ipv6 entries.

logicearth said:

If its really that much of a problem why don't you just turn off IPv6?
But now I wonder what problem is this actually causing?

1. Applications are failing to react according to IP address, because the IPv6 address is being presented. Even though the IPv6 address is zero compressed, it is inconsistent in its format, and is not predictable. 192.168.1.x is and I can make several assumptions in my programming, which I cannot in IPv6.

2. I cannot remember 21 IPv6 addresses off the top of my head. I can with the IPv4 because only the last octet changes. The IPv6 addresses have 3 compressed octets, leaving 5. The first fe80 is constant, the other four I ave to try and remember. I could carry around a "translation" card with me everywhere so I can refer to that.

There is more but I won't bore you with the details.

The point of my original post was "What changed to make the IPv6 address be presented instead of IPv4".

You cannot totally turn off IPv6. Yes, I know I can untick it in the connection properties. Indeed, the registry change I presented in my previous response was infact doing that at a lower level. It even says that you would still see the tick on the exact area the you highlighted, but it would not actually be active.

But, again, what I originally wanted to know was, since nothing had changed except the installation of a .NET 4 patch or two on ONE machine, ALL machines EXCEPT the server started presenting IPv6 addresses and I wanted to find out why.

The first step in fixing anything is understanding the problem and what caused the problem. The theory was if I can identify what caused the change to occur I could reverse it and all would be well. At the time I thought that would be a more expedient resolution than re-writing my applications with a lookup table.

I am well aware that evetually IPv6 will replace IPv4 and I have no isse with that. Like I said - All I wanted to know is what changed that made the IPv6 addresses get shown instead IPv4. Things dont magically change by themselves.

The only thing I could identify was the removal of the XP machine, which was replaced with a WIndows 7 machine, because that is when the addresses changed.

logicearth said:

You know you can set you IPv6 addresses to be anything you like?
Instead of relying on the pesudo-random IP Windows makes.

Then you could run 20 IPv6 address from the top of your head...tho why anyone would need to is beyond me. I've been working with networks for way to long and never needed to remember any IP off the top of my head.

thanks for your reply. I was unaware that I could modify the addresses. If such be the case, I can emulate a static environment muh like IPv4 intuitively provides.

It has always been helpful for me to be able to grab an IP address straight out of my memory when working at client PCs.

I too have been around computers too long. I started on Honeywell mainframes in 1978, then onto IBM in 1984. I started working with PCs in 1984. Sadly, I was demoted to management in 1990 and started to lose track of the technical side of things, which is why I seem to have these gaping holes in my knowledge.. But, I digress.

In any case, I think the matter is resolved. The registry changes worked. I've now applied this to all PCs, and for all intents and purposes, my network is now responding exactly as it did before I removed the XP server.

I surely would like to know exactly what caused the change in the way systems responded to ping/tracert etc.. I struggle to accept that simply removing an XP system affected the way every other machine, except the new server, behaved.

oh, one other thing... can you point me to any links that talk about configuring your own IPv6 addresses. I'm guessing there are rules??

thanks
Tanya

Hey Tanya, I found this old post doing a search and figured I would chime in although you have probably figured this out by now.

If you enter -4 after the ping request then it will resolve with the proper IPv4 address, example> ping Garage-pc -4 returns IPv4 addresses, if you enter nothing then the default is for IPv6 addresses to be returned. :)

Hi All,
I know this is old, but I have just started to experience this.
But, with one twist.
One particular PC on the network is returning the ipv6 address instead of the ipv4.
However, most of the other PC's I ping comes back with an ipv4 address.
And it did not use to be like this.
I don't know what the user did, or even if it is coming from the AD server.
I find this very strange.
Anybody have any ideas?

Jerry