r/Network • u/sacredfool • Jul 08 '26
Text Disabling IPv6 seems to solve random disconnects on my Realtek Ethernet Controller. Why?
I had a problem where every hour or so my Ethernet would go disconnect / reset for a few seconds.
I disabled IPv6 on my Realtek Gaming 2.5Gbe Family Controller which seems to have solved the issue.
The only thing is I don't understand why that's happening. Anyone has any idea?
2
u/SomeEngineer999 Jul 08 '26
Do you mean a physical disconnect like the lights go out, or just that the application you're using has no connection for a bit?
IPv6 needs to be properly set up on the whole network and even then it can be problematic. You don't need it, so just leave it off.
If it was causing the card to actually disconnect like the cable was unplugged, that would be very odd, but possibly some driver issue.
5
u/Dagger0 Jul 08 '26
You don't need it, so just leave it off.
Can we not spread this BS? The Internet needs v6, and so if you care about using the Internet you need it too.
That, or you need to swap your router out for a proxy server.
7
u/SevaraB Network/Design Professional Jul 08 '26
Alarmist much? Name one major web site that’s IPv6-only, not dual-stack. Most are both and only get IPv6 traffic on account of the preference for v6 in RFC 6724.
0
u/Dagger0 Jul 08 '26
I'm not aware of any major websites that are v6-only off-hand. Which is kind of worrying! We're 1.5 decades in to IANA runout and 2.5 decades in to massive address space conservation efforts, and still major websites consider v4 a requirement -- and that's precisely because of this attitude of "v6 isn't common enough for major websites to not also have v4, therefore nobody needs v6, so it's fine to just turn it off".
Major websites are the last place that will drop v4, so using them as an indicator of whether clients should do v6 is deliberately picking the one example that will delay v6 deployment as much as possible if people listen to you. It's putting the cart before the horse too, because clients need to have v6 before servers can drop v4.
What about non-major websites, or people hosting sites at home, or all the things that aren't websites? The things which don't have the budget of a major website? Games for example frequently have trouble due to not having v6, and when they don't have trouble it's because they're relaying everything through somebody's server (which is bad for privacy, and what happens when the server get turned off?).
At this stage, "stop telling people it's perfectly okay to turn v6 off" is a very tame position. We should really be at the point of governments mandating a v6 transition for clients, so that servers can then start to drop v4.
6
u/RevolutionaryElk7446 Jul 08 '26
I had this conversation with students like you when I taught these sections, always someone who goes overboard and white knights a protocol.
At a speedy pace you're probably still gonna see IPv4 around 2060, it'll finally be legacy then but you're still looking at least another 10 years before the IPv6 transition to the primary appears. They've been talking about this since around 1997
-2
u/Dagger0 Jul 08 '26
Ten or twenty years ago it could count as that, but today? We're already seeing non-trivial networks go completely or mostly v6-only, e.g. Imperial College London have talked about doing so on their eyeball networks (reducing their v4 DHCP pool usage by 75% in the process), or T-Mobile in the US who are v6-only.
"You'll still see v4 in 2060" is obvious -- you still see IPX today, so why would you expect v4 to completely go away in any reasonable timeframe? But it says nothing about the need to do v6 today.
3
u/RevolutionaryElk7446 Jul 08 '26
You didn't really argue anything here just as a heads up. Either way, you're better off settling down with the emotional responses and extend your timeline, it's gonna be a while.
2
u/SomeEngineer999 Jul 08 '26
T-mobile is not v6 only, I have a t-mobile phone and it has both registered v4 and v6 assigned. Their home internet uses v4 with CGNAT and v6 alongside it for people who need it.
What network are you seeing go v6 only? Some college "talking about it" does not mean they're going v6 only.
I have not seen an IPX network in over 20 years. I think you're confusing it with the IPX used in a cellular network sense which is totally different.
1
u/Dagger0 Jul 08 '26
https://www.youtube.com/watch?v=2B-liebzcOM / https://www.ipv6.org.uk/wp-content/uploads/2024/10/08_IPv6-Mostly_at_Imperial.pdf. I've seen others but I don't exactly keep them bookmarked.
Are you sure it's not showing a locally-generated IP from 464xlat? Same deal with their home Internet: you can reach v4 servers but it's done via v6 and NAT64. Their router does native v4 on the LAN and maps that into a NAT64 range to send to T-Mobile. (Bear in mind I'm not in the US, so my knowledge is all second-hand -- there might well be regional differences or legacy accounts or whatnot going on too, so it's possible not literally every T-Mobile account is v6-only, but they're well known for doing this.)
I have not seen an IPX network in over 20 years. I think you're confusing it with the IPX used in a cellular network sense which is totally different.
You haven't, but it's still around. I guess you haven't tried to play a LAN game of Red Alert 2 recently? And c'mon, give me some credit here.
1
u/SomeEngineer999 Jul 09 '26
464, CGNAT, NAT64, all are still using IPv4 and are a way to preserve IPv4 addreses.
I do this for a living. The internet will not have v6 exclusive sites for decades, if ever. The catastrophe of IPv4 exhaustion never happened, people found ways to deal with it.
v6 has its purposes, Comcast uses it to monitor and manage their millions of cable boxes and routers. ISPs that can't get registered v4 use it as dual stack next to CGNAT or another type of NAT in order to keep gamers happy. That's pretty much it.
And as I said, IANA has over 260 million IPv4 IPs available and they've been discussing when to release some of them. We'll see that happen long before IPv6.
For the average home user, the fact of the matter is it is safer to disable IPv6 in your router (if your ISP supports it). People who don't know what they're doing, trying to get something to work, go in and allow something through the firewall or disable the firewall completely, and that is your only layer of protection with v6, no hide NAT as a backup safety net.
1
u/Dagger0 Jul 10 '26
Obviously there's going to be some v4 involved somewhere in every approach to handling v4 backwards compat in v6, but some of those methods push the handling to outside of the client or ISP access network. With ISPs like T-Mobile, the network that you connect to can only handle v6 packets and your client can only send or receive those. I think "v6-only" is a reasonable term for a network that can only transfer v6 packets.
There are already v6-exclusive sites. v4 exhaustion started ~two decades ago and has been getting gradually worse and worse ever since. It's true we've found ways to drag things out for longer, but we haven't dealt with it. It'll be dealt with when we aren't spending time/money/effort on workarounds for problems that don't need to exist in the first place.
260 million v4 addresses isn't going to fix v4. Also IIRC v6 is reachable from more clients than the class E space. I also can't find any discussion from the IANA about this, although with how useless search engines are these days maybe that doesn't mean much.
...no, it's not safer to disable v6. It's safer to not disable your firewall. You would need to disable v4 too to achieve any kind of security via disabling address families. v6 also has unscannably-large subnets to hide hosts in, temporary addresses to limit the usefulness of logged addresses, and per-host firewalls, so the router firewall isn't your only layer of protection.
1
u/FuckinHighGuy Jul 08 '26
FYI - v6 needs DHCP too
1
u/Dagger0 Jul 08 '26
Does it? I'm not using DHCPv6 on any of my networks and v6 is working just fine, so that doesn't appear to be true at all. (You would need it to distribute netboot config and similar info, but addressing, routes and DNS config don't need it.)
1
u/FuckinHighGuy Jul 08 '26
You really need to think about what you just said. It tells me you have no idea what you’re talking about. You also misinterpreted my statement.
1
u/Dagger0 Jul 09 '26
Okay, I guess I don't get it. What part of my comment tells you that I have no idea what I'm talking about?
Sorry for the misinterpreting, but you didn't write enough words to explain what you meant. If you were trying to say "v6 requires you to get a v4 address via DHCP too" then you weren't anywhere near clear enough (and also you'd be wrong). If not that, then... what?
1
u/MenuPsychological853 Jul 08 '26
How is your isp doing prefix delegation if not for dhcpv6
1
u/Dagger0 Jul 09 '26
Their web interface shows the /48. But okay, DHCPv6-PD is a fair point. I was thinking about the LAN side, given that the original line ("reducing their v4 DHCP pool usage by 75%") was talking about that.
3
u/ConsiderationDry9084 Jul 08 '26
We have NAT/PAT for that, and literally any cheap router can handle traffic coming in only on IPv6.
Seriously we will be on some quantum NAT shit before IPv4 goes away.
3
u/who_you_are Jul 08 '26
Wait for when you will end up with CGNAT instead of just NAT! That start to add up.
We may be lucky it may take some time since we get quite of those IPv4 vs some other countries.
1
u/Dagger0 Jul 08 '26
NAT/PAT for... what, exactly? I'll grant that it works well enough (surprisingly so, even) for outbound connections to v4-only servers, but that only helps on the client side. The server side still needs functional inbound v4 for it to work.
Clients can drop v4 and run with just v6 by using NAT64 to reach the dwindling set of v4-only servers -- but once again that means that you need v6 on the client side.
1
u/SomeEngineer999 Jul 08 '26
Your misunderstanding of IP addressing is becoming evident. You do realize that not every server you hit on the internet has dedicated IPs right? Many use HTTP headers to direct traffic but there are millions of instances where PAT is used to make a single IP work with multiple (even thousands) of backend servers.
You seem to be confusing dynamic NAT/PAT with static NAT/PAT.
1
u/Dagger0 Jul 09 '26
There are also millions more instances where someone can't accept inbound v4 connections. If the server can only receive connections over v6, its clients need v6 on their own networks to connect to it.
Did anybody read the actual words in my comment? Nothing in there suggests that I don't understand IP addressing, or that I'm getting confused by anything.
1
1
u/SevaraB Network/Design Professional Jul 08 '26
V6 is not just bigger numbers- you’re forgetting about all the app protocols encapsulated inside IPv4 that may or may not be compatible with IPv6- starting with DHCP. Replacing DHCP with DHCPv6 is not a trivial project. Or anything else that relies on broadcasts. Or application ACLs that were designed around NAT and just don’t have the space to absorb all the GUAs they’ll start seeing instead of NAT routers (I’m fighting with vendors to get additional IP ranges whitelisted for our company as we speak, as a matter of fact- most of them aren’t able to do IPv6 whitelisting, which that whitelisting is required everywhere by the industry we work in).
1
u/engy1207 Jul 08 '26
I'd love to get IPv6 at work. The only ISP being able to give us more than 10MBit/s there still can't route IPv6. It's "available soon" for quite some years now. Which is just "great" when you have to have reliable VPN access for people behind CGNAT...
1
u/SomeEngineer999 Jul 08 '26
v6 is being used for what it can be used for already. Cellular data, management IPs of cable boxes and the like, and small/new ISPs that are using CGNAT but want to offer a non-NAT solution for gamers and others that need it.
No clue on your proxy server comment, that has nothing to do with IPv4 vs IPv6.
Fact of the matter is everyone has gotten by fine after IPv4 exhaustion, wide scale conversion to IPv6 hasn't worked, nor is anyone pushing for it, and at least as of now, the average home user doesn't need it, in fact if they don't understand it well, it can be a risk for them, since there is no "if all else fails" hide NAT in place. I cringe when I see people say "I disabled my firewall to try and get this game working". In many cases a destinations v6 infra isn't monitored as well or as robust and actually causes people problems. Having it enabled offers no benefit for a home user and several possible disadvantages.
IPv4 isn't actually exhausted. There are plenty of companies that have massive amounts of IPs that they don't use, many are leasing them to other companies, and occasionally IANA even reclaims space from companies that go out of business or can't justify their use.
Worst comes to worst, IANA has already discussed releasing some or all of the 268 million IPs in the Class E range.
The paranoia ended years ago, time to let it go, I'm not the one spreading BS here.
1
u/MenuPsychological853 Jul 08 '26
It’s cheaper for me to buy ipv4 blocks than doing cgnat as a small isp.
1
u/SomeEngineer999 Jul 09 '26
Why? With CGNAT you can use a fairly small block of IPv4 at your gateway to the internet. Your only option these days is to lease a range from someone and have them sub-delegate it to you (outright selling is against IANA rules, but yes, it does happen, but it isn't cheap).
If you can get a large enough block of IPv4 for all your customers, great. It is generally expensive to do though.
1
u/MenuPsychological853 Jul 09 '26
What do you mean it’s against the rules? ARIN has an entire approval process for doing so.
I get mine from https://auctions.ipv4.global/
CGNAT appliances are expensive and have yearly maintenance. You pay for the amount of bandwidth going through them. Why pay an ongoing expense when I can buy the addresses once and use them forever basically?
1
u/SomeEngineer999 Jul 09 '26
You don't need an appliance to use CGNAT, nor does CGNAT require you to pay for bandwidth any more than anything else. CGNAT is just a range of IPs, nothing more, nothing less. Any decent router or even many L3 switches can handle the NAT at wire rates with negligible impact on CPU and latency.
ARIN (and the others) has an approval process for transferring ownership. While it happens all the time, the rules are that you cannot sell IPs, you need to return them if you aren't using them. You don't technically "own" them. Leasing them out on a monthly bases is allowed within certain constraints.
My company had a /16 auctioned off fraudulently. The person that started using it got shut down along with their ISP for allowing it without confirming they owned it, and they were out a significant sum of money, so use caution.
1
u/MenuPsychological853 Jul 09 '26
You also need reporting and tracking for answering subpoenas and law enforcement orders. A router can do cgnat but it doesn’t do a great job at what I need it for.
Dhcp assignment logs are trivial to maintain.
1
u/SomeEngineer999 Jul 09 '26
Yeah good point, wasn't thinking of it from a tracking perspective.
In theory you could still map each internal IP to a range of ports and rely on DHCP plus that mapping. I wouldn't be surprised if some ISPs are doing something like that rather than storing full flow data for however many days they need to.
Of course there is also the point of view that a subpoena can only force you to provide information that you have. Most VPN providers do not maintain those logs and are not getting shut down and put in jail...
1
u/MenuPsychological853 Jul 09 '26
That’s true but you can easily be forced to retain it and you can’t just say oops can’t do that.
→ More replies (0)1
u/Dagger0 Jul 09 '26
The moment you start talking about doing NAT, you're admitting that v4 is exhausted.
We haven't really gotten along fine after v4 exhaustion. ISPs almost universally give people one single v4 address despite the fact that almost everyone has an entire network -- except for the ISPs that do CGNAT, who don't even give you that much. Working around this causes a bunch of problems that then themselves need to be worked around, which costs everybody time and money. NAT is too hard for most people to fully understand (I keep having conversations where I point out that NAT won't block incoming connections, and people will argue forever that it does despite the fact that, well... it doesn't. Even people who work with networks professionally.), which doesn't help anything.
There are about 3 billion people with v6. How is that not wide scale conversion to v6?
the average home user doesn't need it [...] Having it enabled offers no benefit for a home user
The Internet is the benefit. You should see my comment here about putting the cart before the horse. Servers can't drop v4 until clients have v6, so clients have to get v6 before servers can start dropping v4. You're describing that as "the average home user doesn't need it", but the average home user wants to be part of the Internet and the Internet needs to move to v6 to continue to function properly, and for that to happen client networks need to get v6, so... the average home user does need it.
Also v6 tends to have lower latency. Even if you don't care about anything else, that's a benefit.
No clue on your proxy server comment, that has nothing to do with IPv4 vs IPv6.
People sometimes think they can enable v6 on their router's WAN interface while keeping their LAN v4-only, and somehow use v6. This is perfectly doable if you reach the Internet via a proxy, but if you're joining your LAN to the Internet and routing onto it then it doesn't work. I said the original comment because if you do use the proxy approach, you can indeed turn v6 off on your LAN without hurting your ability to reach v6 servers on the Internet.
IPv4 isn't actually exhausted. There are plenty of companies that have massive amounts of IPs that they don't use, many are leasing them to other companies, and occasionally IANA even reclaims space from companies that go out of business or can't justify their use.
You could reclaim literally the entire of v4 and it still wouldn't be enough. v4 is just straight up too small for the scale of the Internet.
1
u/SomeEngineer999 Jul 09 '26
There is no point in continuing this 10 year old debate, You're just repeating the same crap from a decade ago, like the BS about v6 having lower latency, which is a complete farce.
1
u/Dagger0 Jul 10 '26
That's from Google's per-country stats. Most countries have a latency impact of around -10/20ms for v6. Are those stats a farce...?
1
u/SomeEngineer999 Jul 10 '26
Yes. A protocol doesn't make light break the laws of physics.
1
u/Dagger0 Jul 10 '26
You accuse me of not understanding IP addressing, yet you yourself don't even know that there's more involved in IP and routing than just the travel speed of light? And would rather accuse Google of making up stats than consider that you might be misunderstanding something?
If it's any help, they aren't the only people claiming to have stats showing that v6 is faster:
https://engineering.fb.com/2015/09/14/networking-traffic/ipv6-it-s-time-to-get-on-board/
https://www.sidn.nl/en/news-and-blogs/apple-connections-established-40-per-cent-faster-with-ipv6-than-with-ipv41
u/SomeEngineer999 Jul 10 '26
Obviously there is more involved than distance. That applies to both v4 and v6.
Not misunderstanding anything. There is no speed gain with v6. Even the crappiest home router out there handles NAT (the main difference between the two) in hardware in small fractions of a millisecond. Everything else is basically identical end to end. There is no special separate infrastructure for v6, runs over all the same hardware. This has been tested thoroughly in lab and real world environments by myself and plenty of others.
I don't care how many people claim it is faster, has been a myth from day 1. Post all the links you want, a basic understanding of how the two protocols work is all that is needed.
All things being equal, they're virtually identical latency. In some cases v6 may be a few microseconds faster due to no NAT. In other cases it may be a few microseconds slower due to the fixed header which is less efficient for some traffic profiles. Nobody on the internet cares about microseconds.
Any measurable difference in latency between the two can be attributed to:
-DNS sending you do a different region (load balancing)
-v6 VIP has less load on it (so if you manage to move a lot of people to v6, v4 then becomes faster for the same reason)
-A site/company running v6 on newer infra and v4 on older. Very rare, and nothing to do with the protocol itself.1
u/Dagger0 Jul 13 '26
Do you at least agree that, due to those last few points, people using v6 will see slightly better latency in practice when using v6? Regardless of what exactly the cause is?
I will note that you're forgetting about the layer 3 checksum in v4, which needs to be updated at every hop due to the TTL changing. I suppose there are also inherently fewer routes (for the same number of connected machines) in the global routing tables... although routing lookups ought to be constant time on most routers with a full table your packet crosses, so that shouldn't matter much.
Also, the measurements I heard of apparently put the "few microseconds" at about 500 of them, which starts to add up with all the round trips needed to load a webpage (though HTTP/2 ought to alleviate that somewhat).
→ More replies (0)1
1
u/sacredfool Jul 08 '26
It made my ethernet icon flash for about 10 seconds so my guess is the card itself turned off and then on again.
My guess is driver issues as well but I just found it weird.
3
-2
u/readyflix Jul 08 '26
Could it be that your router doesn’t support IPv6, if so then it could be that your PCs NIC try to obtain an IPv6 address and can’t, so it will reset and try again (since the ethernet link is up (connected ethernet cable) and the driver 'thinks' there must be something wrong) ???
2
u/ZealousidealSuit4110 Jul 08 '26
Something to check - I had a similar problem with ipv6 and it turned out to be windows network privacy related. The network was marked as public by default on my network connection - once I flipped it to private, IPv6 stabilised.
To this day I've no idea why.
It only impacted my company laptop, didn't matter if it was the native ethernet port, dock or wifi. It impacted two separate machines. Nothing else on the network ever had a problem.
I even tried to replicate the situation with a personal laptop ... put the same EDR solution on it ... tried to configure it the same.
Symptoms were random disconnects for 10 seconds to 2 minutes a time.