Router is acting weird all of a sudden.

Hello. I've ran into an interesting issue.
My internet connection goes down for like 3~ sec randomly. It could be 3 times a day. Maybe once a day. Anyways its really annoying especially in games.
So I found a ping script online. It basically pings google every 5 seconds and if it doesnt get anything back it initiates a tracert. The script gives precise time too.

Now. My router is ASUS RT-AC57U. latest firmware. Since I have a precise time when the wan connection goes down I checked system logs in router page and it says 2 interesting lines.

Mar 9 17:37:24 kernel: ESW: Link Status Changed - Port0 Link Down
Mar 9 17:37:26 kernel: ESW: Link Status Changed - Port0 Link UP

This started happening around a week ago, before that everything was normal, no issues at all. Im thinking it could be the latest firmware(Maybe i should downgrade), but this is really annoying. I already contacted ISP and they checked and said that this is an issue on my side.
Anyways I tried reflashing the new firmware again. Because the old error was (To specifiy I was getting these 4 lines before I reflashed the same firmware again, after reflashing im getting port link down, port link up)

Mar 9 17:31:49 kernel: MTSmartCarrierSense(): CSC=M
Mar 9 17:31:52 kernel: MTSmartCarrierSense(): CSC=L
Mar 9 17:33:19 kernel: MTSmartCarrierSense(): CSC=M
Mar 9 17:33:29 kernel: MTSmartCarrierSense(): CSC=L

Now I in fact have another router. Its an ASUS RT-N12+. And it works without the problem. But I just don't understand how just randomly my more expensive and better router just started spitting out error's and having connectivity issues.
 

beers

Moderator
Staff member
Do you have another cable for the eth0 connection? That seems like a physical layer issue to me. Usually you wouldn't see the actual interface bounce like that, which would definitely wreck your traffic for a second or two.
 
Do you have another cable for the eth0 connection? That seems like a physical layer issue to me. Usually you wouldn't see the actual interface bounce like that, which would definitely wreck your traffic for a second or two.
Okay. Gonna try a new cable then.
 

Pupp

Member
You'd be better of using WireShark. And there are much better programs for tracing than tracert. Ok, the good ones cost money.

You could try doing a hard reset on the router. Of course there is the possibility your router is going bad. Is it under warranty still?

You might look at the IPv4 and IPv6 settings. At this point, you can disable IPv4, if it's enabled.

There was a very long overlap between IPv4 and IPv6, but that wrapped up at least by the end of 2020, but maybe even earlier. In any event, IPv4 doesn't really exist anymore, so anything left of it, is just IPv6 wrapping IPv4 packets into IPv6 packets, and we're really just talking Windows 7 maybe. I don't think even outdated routers and stuff can operate on the internet. But personal computers can still get away with it, but it's really just old, outdated Windows OS like Windows 7 that had that issue, and that was probably fixed by Microsoft years ago.
 
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beers

Moderator
Staff member
You'd be better of using WireShark.
Write up a multi-page guide telling him what he should specifically look for in that case.

At this point, you can disable IPv4, if it's enabled.
This is the worst advice ever given. Have you ever even used a v6-only network with no NAT64?

Obvious troll, gtfo.
 

voyagerfan99

Master of Turning Things Off and Back On Again
Staff member
This is the worst advice ever given. Have you ever even used a v6-only network with no NAT64?
Exactly. IPv4 is still in use worldwide. IPv6 is just adapted when needed. I haven't even come across IPv6 in the wild besides through an ISP WAN.
 

Pupp

Member
I said that IPv6 just wraps IPv4 when needed. But most modern equipment, since 2012, has been IPv6 by default. Yes, there is a lot of IPv4 still in use, but for the most part, it's just dealt with by IPv6 equipment.

Cell phone pretty much are straight IPv6 devices, so just about any website that wants a cell phone to connect to it, will be using IPv6. But like I said, IPv4 is just dealt with by IPv6 equipment, so that only networking nerds would even think about IPv4 or IPv6.

If you look at Windows 10's Command Line Interface (CMD), and type in ipconfig, Windows will give you both it's IPv6 and IPv4 address. I assure you that the IPv4 is used for backward compatibility. Yes, you can still get IPv4 websites, but it will be wrapped in an IPv6 envelop at some point before it get's to your computer. It's more likely that the IPv4 address would be used in an intranet, like at a college, or an office building.

In any event, you wouldn't disable IPv4 on your Windows computer (if that's even possible), but the router.
 
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Pupp

Member
This sentence makes zero sense.
I don't know if it's possible to actually disable IPv4 anyway. It's nearly a moot point since nearly the entire internet is IPv6 now.

The most basic way to explain IPv6 is that it's a bunch of alpha-numeric numbers. (hexadecimal) Essentially to wrap an IPv4 packet, it just attaches the IPv4 part at the end of the IPv6, essentially just using the last few digits for that. If you look at ipconfig, the gateway might have a combination IPv6/IPv4 address. The last section is so that humans can actually read the address and know what the IPv4 address is, although in reality, it's actually just broken out by the computer (or other networking equipment), in a way that humans can read. Technically that combination IPv6 address is just a straight IPv6 address, the the hexadecimal coding for the IPv4 address. I have no doubt networking students hate having to convert an IPv4 address into hexadecimal just because the teacher assigned it as homework.

Anyway, I'm not going to comment anymore on a subject that's more at home a computer networking forum. This thread has pretty much went far off the OP's original problem.

But I did have a modem a few years ago (HughsNet), that kept dropping the connection, and the customer support guy said to disable IPv6 on their modem, which worked for a while, until it didn't work at all. I ditched HughsNet after that, so I have no idea if they ever upgraded their crappy system to proper IPv6.
 

beers

Moderator
Staff member
I said that IPv6 just wraps IPv4 when needed.
ut like I said, IPv4 is just dealt with by IPv6 equipment
They're completely different protocols. v6 doesn't magically wrap v4 traffic, they are independent. There are a few 6-to-4 tunneling mechanisms like Teredo which does v6 over v4. You can also use any sort of underlay/overlay network like a transport v6 underlay that the v4 overlay network has no idea about or even a v6 posture over a v4 VPN as an example. The protocols themselves don't auto wrap that traffic and are considered separate stacks (see terms like dual-stack network). It's impossible to reference addresses across stacks without an intermediary protocol or mechanism like NAT64.
I have no doubt networking students hate having to convert an IPv4 address into hexadecimal just because the teacher assigned it as homework.
If you converted a binary value from hex for v4 to v6 you will have a different address value between protocols and your resultant v6 value isn't routable address space across the internet. Conversely you cannot fit 128 bits into a 32 bit field when attempting to convert from v6 to v4, so it's not really a thing.

Most people would NAT64 the entire IPv4 address space into a /64 prefix or similar and use that as a routing reference.
 

Pupp

Member
I'm trying to get this back to the OP's original problem (Thank you beers for asking about the original issue.)
But here's a link to a document that can explain it. When the document came out in 2013, there was far more IPv4 equipment that didn't support IPv6.

LINK>>> Translating IPv4 packets into IPv6 packets

This is the relevant text:


4. Translation of IP Packets​



When transporting IPv4 packets across an IPv6 network via the
mechanism described above (Section 3.2), an IPv4 packet is translated
to an IPv6 packet at the ingress AFXLBR, and the IPv6 packet is
translated back to an IPv4 packet at the egress AFXLBR. IP packet
header translation is accomplished in a stateless manner according to
rules specified in [RFC6145]; the details of address translation are
explained in the next subsection.
 
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