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Mysterious ethernet/internet issue

Started by Unknown October 10, 2018
This is a bit of a long shot, but maybe somebody has seen something like this, I am thinking not but ya never know.

Situation is really weird:

My PC can play World of Warships fine, Company of Heroes via Game Ranger fine.

It can browse/websurf the internet fine.

It can even connect to another laptop over same ethernet port by pulling out internet cable modem cable and reconnecting to laptop etc.

But for whatever reason:

If computers from the outside try to connect to my PC it's not working.

Vice versa it's also not working ?!? Maybe cause those devices are natted.

But as far as I know my PC is not NATTED.

Or it's some strange/new ISP kind of NAT that behaves oddly.

Like only big companies/servers are still reachable and not consumer PCs.

As far as I can tell my PC does have a public IP address.

But apperently this is not working/enough anymore ?! Very strange.

I plan on replacing my PC with a laptop, just as a test, to see if it's the PC at fault and it's software, or if something more strange is going on ?!

What kind of electrical defect/or wear and tear could produce such a weird result ?!

(One thing which is on my mind is something different, a hacked or misconfigured/corrupted modem, which somehow blocks this).

For now I will keep assuming that everything is just fine on my PC and that it's the outside world that simply can't connect to my PC.

Though even laptop <> PC sometimes behaves weird as far as I can recall, but usually I can get it to work (?!) though now I am not so sure anymore.

It's not stupid firewall cause this is turned off and would usually allow anyway... it's something more strange.

I will try to get to the bottom of it though.

Also is there any service out there on the internet where there is a public computer that can send some traffic to a specific tcp or udp port ?!

Just to see if my PC can actually receive this ?!

That would be very helpfull.

Bonus would be if I can then send something back to it's udp or tcp port to see if that computer can also receive from me... and finally it reports this via a website/html or so... or even e-mail or so.

Bye,
  Skybuck.
On Wednesday, October 10, 2018 at 9:39:14 PM UTC-4, skybu...@hotmail.com wrote:
> This is a bit of a long shot, but maybe somebody has seen something like this, I am thinking not but ya never know. > > Situation is really weird: > > My PC can play World of Warships fine, Company of Heroes via Game Ranger fine. > > It can browse/websurf the internet fine. > > It can even connect to another laptop over same ethernet port by pulling out internet cable modem cable and reconnecting to laptop etc. > > But for whatever reason: > > If computers from the outside try to connect to my PC it's not working. > > Vice versa it's also not working ?!? Maybe cause those devices are natted. > > But as far as I know my PC is not NATTED. > > Or it's some strange/new ISP kind of NAT that behaves oddly. > > Like only big companies/servers are still reachable and not consumer PCs. > > As far as I can tell my PC does have a public IP address. > > But apperently this is not working/enough anymore ?! Very strange. > > I plan on replacing my PC with a laptop, just as a test, to see if it's the PC at fault and it's software, or if something more strange is going on ?! > > What kind of electrical defect/or wear and tear could produce such a weird result ?! > > (One thing which is on my mind is something different, a hacked or misconfigured/corrupted modem, which somehow blocks this). > > For now I will keep assuming that everything is just fine on my PC and that it's the outside world that simply can't connect to my PC. > > Though even laptop <> PC sometimes behaves weird as far as I can recall, but usually I can get it to work (?!) though now I am not so sure anymore. > > It's not stupid firewall cause this is turned off and would usually allow anyway... it's something more strange. > > I will try to get to the bottom of it though. > > Also is there any service out there on the internet where there is a public computer that can send some traffic to a specific tcp or udp port ?! > > Just to see if my PC can actually receive this ?! > > That would be very helpfull. > > Bonus would be if I can then send something back to it's udp or tcp port to see if that computer can also receive from me... and finally it reports this via a website/html or so... or even e-mail or so. > > Bye, > Skybuck.
Local networking with Win2K was not very hard. Networking with anything newer is a PITA and will work or not work randomly. I spent a bunch of time trying to get two similar PCs sitting next to one another to share files. It would work one direction and not the other. I could remote desktop sometimes and other times not. It never worked reliably. I could never find anyone with info on how to *actually* make it work. Web sites often just lift solutions from one another and sometimes come up with incredibly arcane solutions that have potential of doing damage. It's a jungle out there. Rick C.
On 11/10/2018 12:39 pm, skybuck2000@hotmail.com wrote:
> This is a bit of a long shot, but maybe somebody has seen something like this, I am thinking not but ya never know. > > Situation is really weird: > > My PC can play World of Warships fine, Company of Heroes via Game Ranger fine. > > It can browse/websurf the internet fine. > > It can even connect to another laptop over same ethernet port by pulling out internet cable modem cable and reconnecting to laptop etc. > > But for whatever reason: > > If computers from the outside try to connect to my PC it's not working. > > Vice versa it's also not working ?!? Maybe cause those devices are natted. > > But as far as I know my PC is not NATTED. > > Or it's some strange/new ISP kind of NAT that behaves oddly. > > Like only big companies/servers are still reachable and not consumer PCs. > > As far as I can tell my PC does have a public IP address. > > But apperently this is not working/enough anymore ?! Very strange. > > I plan on replacing my PC with a laptop, just as a test, to see if it's the PC at fault and it's software, or if something more strange is going on ?! > > What kind of electrical defect/or wear and tear could produce such a weird result ?! > > (One thing which is on my mind is something different, a hacked or misconfigured/corrupted modem, which somehow blocks this). > > For now I will keep assuming that everything is just fine on my PC and that it's the outside world that simply can't connect to my PC. > > Though even laptop <> PC sometimes behaves weird as far as I can recall, but usually I can get it to work (?!) though now I am not so sure anymore. > > It's not stupid firewall cause this is turned off and would usually allow anyway... it's something more strange. > > I will try to get to the bottom of it though. > > Also is there any service out there on the internet where there is a public computer that can send some traffic to a specific tcp or udp port ?! > > Just to see if my PC can actually receive this ?! > > That would be very helpfull. > > Bonus would be if I can then send something back to it's udp or tcp port to see if that computer can also receive from me... and finally it reports this via a website/html or so... or even e-mail or so. > > Bye, > Skybuck. >
Lookup 'port forwarding' and/or firewall settings for your gateway/router. -- Cheers, Chris.
On 2018-10-10 18:39, skybuck2000@hotmail.com wrote:
> As far as I can tell my PC does have a public IP address.
Well don't leave us in suspense. What is it?
>"I could never find anyone with info on how to *actually* make it work."
It's worse than all that. I made it work but couldn't begin to tell you how. ...
On Thursday, October 11, 2018 at 7:09:14 AM UTC+5:30, skybu...@hotmail.com wrote:
> This is a bit of a long shot, but maybe somebody has seen something like this, I am thinking not but ya never know. > > Situation is really weird: > > My PC can play World of Warships fine, Company of Heroes via Game Ranger fine. > > It can browse/websurf the internet fine. > > It can even connect to another laptop over same ethernet port by pulling out internet cable modem cable and reconnecting to laptop etc. > > But for whatever reason: > > If computers from the outside try to connect to my PC it's not working. > > Vice versa it's also not working ?!? Maybe cause those devices are natted. > > But as far as I know my PC is not NATTED. > > Or it's some strange/new ISP kind of NAT that behaves oddly. > > Like only big companies/servers are still reachable and not consumer PCs. > > As far as I can tell my PC does have a public IP address. > > But apperently this is not working/enough anymore ?! Very strange. > > I plan on replacing my PC with a laptop, just as a test, to see if it's the PC at fault and it's software, or if something more strange is going on ?! > > What kind of electrical defect/or wear and tear could produce such a weird result ?! > > (One thing which is on my mind is something different, a hacked or misconfigured/corrupted modem, which somehow blocks this). > > For now I will keep assuming that everything is just fine on my PC and that it's the outside world that simply can't connect to my PC. > > Though even laptop <> PC sometimes behaves weird as far as I can recall, but usually I can get it to work (?!) though now I am not so sure anymore. > > It's not stupid firewall cause this is turned off and would usually allow anyway... it's something more strange. > > I will try to get to the bottom of it though. > > Also is there any service out there on the internet where there is a public computer that can send some traffic to a specific tcp or udp port ?! > > Just to see if my PC can actually receive this ?! > > That would be very helpfull. > > Bonus would be if I can then send something back to it's udp or tcp port to see if that computer can also receive from me... and finally it reports this via a website/html or so... or even e-mail or so. > > Bye, > Skybuck.
What are you using to connect to the INternet - ADSL or cable modem ? In any case, each of these devices acts as a router on the LAN side, and must have NAT and port forwarding enabled, and can be configured to block any incoming packets of one's choice. Also all PCs these days have a firewall, and the firewall can be configured(on Linux iptables) to allow/block any packet of choice. This effectively provides two layers of protection. Note that NAT and port forwarding work only at the modem level, not on the PC. So aome more details of your setup is needed before a clearer picture emerges.
On Thursday, 11 October 2018 08:08:44 UTC+1, daku...@gmail.com  wrote:

Your service provider may have activated "carrier grade NAT".  This
allows many customers to share the same IPv4 address at the same time.
It makes it completely impossible for incoming traffic to reach your
network, regardless of how you set your router.  The only traffic
that can reach you is replies to your outbound traffic.

Unfortunately, this is becoming much more common.  Ask your service
provider if they are doing this.

Also ask if IPv6 is available.  There are vast numbers of IPv6
addresses available, so CGNAT is not needed.

John

On Thursday, October 11, 2018 at 9:08:44 AM UTC+2, daku...@gmail.com wrote:
> On Thursday, October 11, 2018 at 7:09:14 AM UTC+5:30, skybu...@hotmail.com wrote: > > This is a bit of a long shot, but maybe somebody has seen something like this, I am thinking not but ya never know. > > > > Situation is really weird: > > > > My PC can play World of Warships fine, Company of Heroes via Game Ranger fine. > > > > It can browse/websurf the internet fine. > > > > It can even connect to another laptop over same ethernet port by pulling out internet cable modem cable and reconnecting to laptop etc. > > > > But for whatever reason: > > > > If computers from the outside try to connect to my PC it's not working. > > > > Vice versa it's also not working ?!? Maybe cause those devices are natted. > > > > But as far as I know my PC is not NATTED. > > > > Or it's some strange/new ISP kind of NAT that behaves oddly. > > > > Like only big companies/servers are still reachable and not consumer PCs. > > > > As far as I can tell my PC does have a public IP address. > > > > But apperently this is not working/enough anymore ?! Very strange. > > > > I plan on replacing my PC with a laptop, just as a test, to see if it's the PC at fault and it's software, or if something more strange is going on ?! > > > > What kind of electrical defect/or wear and tear could produce such a weird result ?! > > > > (One thing which is on my mind is something different, a hacked or misconfigured/corrupted modem, which somehow blocks this). > > > > For now I will keep assuming that everything is just fine on my PC and that it's the outside world that simply can't connect to my PC. > > > > Though even laptop <> PC sometimes behaves weird as far as I can recall, but usually I can get it to work (?!) though now I am not so sure anymore. > > > > It's not stupid firewall cause this is turned off and would usually allow anyway... it's something more strange. > > > > I will try to get to the bottom of it though. > > > > Also is there any service out there on the internet where there is a public computer that can send some traffic to a specific tcp or udp port ?! > > > > Just to see if my PC can actually receive this ?! > > > > That would be very helpfull. > > > > Bonus would be if I can then send something back to it's udp or tcp port to see if that computer can also receive from me... and finally it reports this via a website/html or so... or even e-mail or so. > > > > Bye, > > Skybuck. > > What are you using to connect to the INternet - ADSL or cable modem ? In any case, each of > these devices acts as a router on the LAN side, > and must have NAT and port forwarding enabled, > and can be configured to block any incoming packets of one's choice. Also all PCs these > days have a firewall, and the firewall can be configured(on Linux iptables) to allow/block > any packet of choice. This effectively provides > two layers of protection. Note that NAT and port > forwarding work only at the modem level, not > on the PC. So aome more details of your setup > is needed before a clearer picture emerges.
Cable modem: Ubee evm320b Setup is as far as I know: ISP ---- Cable Modem ---- Computer Nothing else. But I am starting to wonder if it's: ISP --- EVIL ISP NAT ---- Cable Modem ---- Computer.
On Thursday, October 11, 2018 at 10:08:07 AM UTC+2, jrwal...@gmail.com wrote:
> On Thursday, 11 October 2018 08:08:44 UTC+1, daku...@gmail.com wrote: > > Your service provider may have activated "carrier grade NAT". This > allows many customers to share the same IPv4 address at the same time. > It makes it completely impossible for incoming traffic to reach your > network, regardless of how you set your router. The only traffic > that can reach you is replies to your outbound traffic. > > Unfortunately, this is becoming much more common. Ask your service > provider if they are doing this. > > Also ask if IPv6 is available. There are vast numbers of IPv6 > addresses available, so CGNAT is not needed. > > John
This is my slight fear. Do you have more information about this ? Product names ? Protocols involved ? Manuals ? Terminology ? If I call my ISP and ask the random guy on the phone: "Are you guys using Carrier-Grade NAT ?" Then I think he may not known what the hell I am talking about ? Guy then probably goes to manager and asks what this is. Another response might be: "No absolutely not". So then I need diagnosis tools, and other tools to prove what really is going on here. Guy might be clueless and give wrong answer or instructed to give wrong answer. I'm thinking of calling my ISP though, just to see if they can help me in whatever way. Though I kinda feel I should first do some proper testing myself... then again if it's indeed this kind of NAT I may be wasting my time on unnecessary testing. I also tried this "first send outbound" data... and then "reconnect to this port". With some tool. But perhaps other side was also behind carrier grade NAT so then again it becomes hard to diagnose this. First I am going to try swapping out my PC for a cheaper/older one... and then re-trying some connect tools so if this does or does not work... But boring and a hassle to do... Bye for now, Tired slightly bored Skybuck ;) :) none of which is your fault btw lol. This posting did make me a bit happy of yours, at least there is somebody else on this planet that knows what might be going on ! ;)
Hmm interesting maybe this can help my PC to communicate with the ISP CGNAT if it's indeed there:

https://tools.ietf.org/html/rfc6887

This wiki mentions it:

https://en.wikipedia.org/wiki/Carrier-grade_NAT

Bye,
  Skybuck.