Windows7 ,Routers and IPV6.

My question is about the network stack of Windows7,but I post here since it is closely related to routers and firewalls and pertains to security anyway.

Windows7 64bits
CIS
Dlink modem- router 2542B

I changed my Router a few days ago and was unable to assign an adress (x.x.x.2) to my first Windows7-64 pc,while pc2 XPPro has no problem getting an assigned x.x.x.3 and pc3 Xubuntu gets without complaining its x.x.x.4.

If I assign its usual x.x.x.2 to my pc1 I immediately lose BB connection.
I remove the assigned number from Network and I get back connection immediately....even if I get the same number I wanted.......
This is weird since I always used D-Link routers this way, albeit the previous router last configuration was really x.x.x.177, x.x.x.146, x.x.x.129 respectively (and it didnt budge for years even though numbers were not progressive).

Now, with Windows7-64 one month old install, its another music.Nothing granted.

I thought the completely useless IPV6 group could be the culprit since in Events Viewer I've spotted repeated DHCPNACK messages to the effect the first DHCP request was denied (but i got immediately after the adress) and the Details provide a “6” which makes me think its due to IPV6 disorienting the router.

In any case I've now completely disabled via Registry all components IPV6 group ,unticked TCPIP6 group in Network and also disabled IPV6 Random Identifier for good measure.

A couple of reboots later the situation seems improved regarding Events DHCP alerts,but I need to ask if disabling this useless -up to now and for a long time still- thing COULD have any after effects security-wise or system-wise.
Losing Homegroup capabilities not a factor for me.

If nobody can bring negative arguments against this disabling,then ,if everything is all right for a few days I'll also try again reassigning my first pc its x.x.x.2 number!

 

A quick Google of the issue doesn't show any clear advantages or disadvantages. At some point it will probably become necessary to use IPv6, but I expect we'll know when. Regarding your IP address issue have you checked to see if there's a router firmware update?

 

That was the first thing I did after setting up broadband.
There's no update available,as v.1.10 is the latests for 2542B.

Apparently, not many people take the trouble to disable IPV6 from their computers. In Windows7 should be easier than in Vista,where it's a difficult move,it seems.

Unless I have trouble with coming updates and/or future Patches trying to put it back, disabling this feature seems to speed up connection.

 

Unfortunately ,disabling IPV6 didnt prevent the usual Event reported error,today right after boot I checked and saw:

'the lease x.x.x.2 of the Network card with adress ...(MAC) ..was denied by server DHCP x.x.x.1.
The DHCP server sent a DHCPNACK message'

This initial error does not prevent the quick assigning of the usual x.x.x.2 adress and all computers work fine, but it is a symptom of something not working 100% as it should.

I'm wondering if the previous x.x.x.177 adress might have been kept and now is interfering.
Perhaps I need to make a flush command of sorts to clear the network card?

 

I haven't found issues with leaving IP6 enabled...when I was running Vista on my laptop, Vista at the office, or Windows 7 at home on two laptops and a desktop PC, and I travel with my laptop to lots of clients, so I'm latching onto many different routers and wireless APs...no problems.

Disabling IP6, you lose some functionality also, like the homegroup setup. While on paper you think that having the OS load IP6 adds overhead...but unless you're running Windows 7 on some Pentium 75 with 64 megs of RAM...it's really not a measurable difference.

I'm wondering, if you're some who has installed/uninstalled a few different antivirus programs, or software firewalls...that the tcp stack/winsock files got a bit whacked, maybe try running a tcp/winsock repair utility to restore those files to virgin default.

 

No,YeOldeStonecat,I didnt install/uninstall a lot at all,windows7 install is only 40 days old and I only changed from Comodo Internet Security with Antivirus to without Antivirus,replacing it with Avira on demand, and keeping Prevx paid all the time.
No chance tcp stack is injured as I have always 'rolled back' with a previous Paragon image as well to prevent such damages.

But..I am using Windows7 - 64bits as it is almost as fast as XP,although I didnt know it could even be installed on a Pentium 75!!!ah!ah!
No,my computer is powerfull enough not to feel the difference,E8400 CoreDuo,3000MHZ,4GygaRAM, still, I have the impression I gained something in speed,perhaps its because on Sundays the line is less crowded.

I dont want to argue with someone of your experience,who also helped me out in the past over a problem, but, I always tried to obey the non written rule that if something is UTTERLY and IRREVOCABLY useless like IPV6, is not expleting any function, is completely redundant and COULD get in the way of working programs should definitely go from a well kept pc.
If and when it is usable it can always put back in place.
I already said losing the Homegroup functionality is not a great loss either for me.
Dont you agree?
If, on the other hand, disabling IPV6 removes other,non specified or even secret, functionalities or it hinders MS updates, it is another matter and I would have to put it back for the well being of the system.

Very strange a program is provided 2 or 3 years from the foreseen capability to use it,though.

Getting back to my pc1 assigned adress problem,what do you think, should I leave things as they are (all is OK) with pc1 given DHCP adress by router on second attempt, pc2 and 3 having the adress I chose, or should I strive to give all of them an adress assigned by me?

 

Might want to peek at some of the functionality that's lost if you uninstall the IP6 stack. There's more network services that Win7 uses that rely on it....even if you're not using IP6 per say. Example..some network discovery stuff related to homegroup, Windows Meeting Space, etc. So I'm not convinced that IP6 is utterly useless anymore, since even though we're not using it as our primary protocol on networks/internet yet....some other network functionality of Windows 7 seems to now be dependent on it.

I remember back when Vista came out...I rushed right out and disabled IP6....but never noticed anything. This old laptop I'm typing from right now as I ride the train back from NYC....Win7, still has IP6 enabled, I never bothered yanking it.

I wonder...if your event viewer errors are related to IP6 not properly binding to your network card.....tried getting updated drivers directly from the NIC manufacturer or motherboard manufacturer? Or just using the old windows drivers that got loaded?

Would be curious in any performance advantages....run a dozen or so online speed tests before disabling it, and then another dozen or so after...to get an average and see if there's any marked increase/decrease.

There's nothing wrong with manaully assigning IPs outside of the DHCP pool.

 

If the router does not support IPv6 (and on quick look this model doesn't) then the IPv6 running on the OS itself is rather redundant.

Well, if it was me, I would certainly strive to do things my way. As to why you cannot assign a .2 address, you should really post ipconfig /all info (with sensitive info masked) for starters.

 

YeOldeStonecat, I cant do comparisons at the moment because I've already made IPV6 removal. Just for experimenting-sake or if anything goes wrong I can always deploy the last image with IPV6 working and make comparisons in reverse. For doing it well I guess I have to distribute the ten speed tests in 7 days or do them in the very same day, to avoid better or worse days.

Seer, please just give me a couple of days as i'll be away tomorrow,too, thanks.

 

Not directly connected with your problem, but here it is. I also used a D-Link router. It was XP certified. In Win7x64 i started having problems with it, with random disconnections usually when the connection was heavily loaded. I googled and found that more people had similar problem but attributed the issue to Realtek drivers. Some others to ipv6. I tried both ways (disabling ipv6 and updating drivers twice) to no avail.

At the end i bought a new router, certified for 7 and my problems are completely gone, i 've re-enabled ipv6 too and the line doesn't disconnect.

 

Wasn't meaning for you to do it, I meant...maybe some other tech site ran some tests and posted the results. Haven't seen any though.

 

thanks for letting me know Fuzzfas........after many years of XP heaven an avalanche of problems with Windows7-64!


Seer & youOldeStoneCat- I just came back and immediately went to the router page: changed DHCP adresses start from
x.x.x.1 to x.x.x.5
hoping to exclude my .2,.3,.4 from active DHCP which could be handy for a fourth pc or access point.
nothing doing-at reboot I always have a green light for DSL in router and pc .3 and .4 work flawlessly
but pc .2 immediately at reboot presents with a yellow of no internet.

I then went to Network Troubleshooting which found the culprit in
DHCP not enabled
(I was flabbergasted MS had solved a problem 1st time in life)
obviously, next reboot, same yellow story no internet.

Then I enabled LMHosts and Netbios over TCP-IP, disabled DHCP in router..........same thing, reboot and voila', no internet.....
This time I checked in Network properties and found that the core of the problem was that the card WILL NOT KEEP the GATEWAY I write on it manually! As soon as I reboot and have no internet on pc.2-while the other two work ok-it is enough to write down in TCP-IP4 after the assigned x.x.x.2 IP and subnet the dlink gateway number 192.168.1.1 that I immediately get back internet connection.......
If I reboot,after saving,adding etc. everything, the gateway -and only the gateway- is lost again........

I looked for a driver for my Realtek PCIe GBE Family Controller and got an update v.7.11.1127.2009 released 11/27/2009, looks the latest, but didnt solve.

It's really frustrating,I will put back a 3 days ago image which is complete with IPV6 and all to start again as soon as I get a clue where to begin.

 

Ah, you have D-Link with Realtek controller motherboard too? Maybe it's not a coincidence...

I am afraid that if you find no software cure, the answer is simply that old (XP certified) D-Link modem/routers , when connected to Realtek ethernet in Win7x64 have problems... I bought a Netgear router now and i can't complain.

 

Fuzzfas,i am afraid you're right.
I'll try a last Realtek drivers update-downgrade today to see if I can manage the only result I care for: the 'keeping of the Gateway' in the network card and if no joy I will buy a new one.
Could you please tell me or pm me the exact model you bought, in order to cut a long story short?

This thing is funny indeed because ,previously, I was using a modem with D-link router DI-604 (max 8 mb/speed),which is definetely older than present 2542B (max 24MB/speed), with Windows7-64bits as well, and the combo was working flawlessly even though was not certified for W7..........
In between I tried DLink 4720 B wireless which also didnt give this problem.

 

I PMed you but i think that pretty much any router with "Windows 7 compatibility" written on the box, should have no issues.

 

I have Homegroup setup on several Win7 PCs at home...the wizard flew right through and set it up nicely. IP6 is disabled on my router since my tiny little cable ISP will probably be the last ISP in the country to adopt IP6. Since IP6 won't be passing to the internet, my router won't be in play with it.

Just like with IP4, if IP6 doesn't detect a DHCP service...it will APIPA itself (automatic private IP address). Just like computers with IP4 would auto assign a 169.254.xxx.xxx address during bootup if they didn't detect a DHCP service..you could still get a functional LAN with APIPA addressing.

Now I've been reading some older networking equipment gets flakey when IP6 is running across it, due to some load IP6 puts on them, the way it multicasts or something. But I've not come across anything like that on my job.

 

IPv6 does not use broadcast addresses, instead it uses different types of multicast (the result is better bandwidth management). So if a device does not support multicast type (or the option is disabled by default) then issues may arise.
BTW, speaking of multicasts, this is somewhat older article, but tells a nice story of practical advantages of using IPv6 in IPTV.

 

Thanks seer for the valuable info. I did not send the ipconfig as I found out why it all comes about.


to sum up:
I have 3 pcs connected,1-Windows7-64
2-XPPro
3-Xubuntu
D-Link 2542B router.
pc 2 & 3 get their internal IP x.x.x.3&4 no problem.
pc1- works only if IP is auto with router DHCP enabled.
If I try to set IP,subnet,and GATEWAY the latter
is 'well received' and connection persists,but as
soon as I reboot the GATEWAY and only the Gateway
numbers just disappear.

I thought it was something peculiar to my computer and router, but I've found at MS forums literally THOUSANDS of poor people even less fortunate than me who have NO connection whatsoever with Windows7 either 32 or 64 bit.

It might be the router not W7 compatible in some cases,but what about the fact that I was using the same brand of DLink dating back 3-4 years for the first 2 weeks of windows7-64 existence and no problem came out of it?

Moreover, I used W7-32 with the same router from April to August last year when it was beta and it worked ok.

So, in my case, its definetely not the router,but for sure is an inconceivable BUG of Windows 7 which made me loose literally days on end for this problem!

Today I tried a possible solution which worked for some,that is, disabling all services while in SafeMode with Networking,and then trying to find the service responsible for the gateway deletion, a move that solved many ( by removing all Apple-Bonjour softwares), but I didnt have that and it failed. I also experienced the gateway loss even with no services running.

The solution might lie in finding the culprit service.......or finding the 'right' driver for nVidia .........perhaps discarding the newest ones and going back to Vista's....
a daunting task in terms of time.........

But, as I already lost one month in my schedule due to windows7 ....'peculiarities', I might as well go to the end of it.

Certainly I like windows7,as it is fast,and with some good points in comparison with XP, BUT I find there is no novelty with Vista as regards the loss of TCP-IP security-see the presence of a connection method which serves WHAT NEED NOW?
Ah, we will have to use it....WHEN?
Someday? In 2012?
And I have to keep a function I dont use now but only in 2-3 years time?..........
Or, is it mandatory to use the Homegroup?
Has file sharing to be active by all means?

It is literally incredible how many people have this problem and not only since a month, as reports were flooding MS forums 5-7 months ago.....
and still no patch no comment no update?

I wanted to doubleboot on this pc,but I am considering using just Ubuntu now.

 

I found the definiteve solution to the problem of the

VANISHING GATEWAY

at TechSupportForums by a poster called Sixtens who had the same problem and solved it on January ,12 this year.

Obviously,it was no router or graphic card,driver or else,but a plain simple Registry bug in windows 7.
A bug which,whatever you run,use or whatever hardware you have, will hit making you lose days trying to find the truth.

The solution is:

run cmd

netsh int ip reset resetlog.txt

After that I restart the computer.

run regedit

Go to the registry key

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
Choose subkey (GUID)

Choose Change and new -> DWORD (32-bit).
Write

DhcpConnEnableBcastFlagToggle in the box New Value #1 then press Enter

Right click over the value
DhcpConnEnableBcastFlagToggle

choose Change.

Give to the "Value data"-box value 1, and press OK.
Exit regedit and restart the computer.


The bug is conquered and there's no vanishing gateway anymore. You write down the numbers and it will finally stick through reboots, hopefully, until you decide a different thing.


I think there are many who suffer from a myriad of network errors who would take advantage of such a neat move, including those showing double or not recognised connections, perhaps I should make another post devoted to this for reference,if any moderator deems that usefull.

I may add that I went on to completely DISABLE IPV6 , including the two Link Layer Topology Mapper and Responder and Random Identifier (all Registry proceedings available on Google).

No more problems ,more security, perhaps more speed.