Question LAN connection already iffy, but plugging in a second LAN makes it crash every 10 ~minutes. [ADSL]

[ashdejan]

Spoiler: Info

If i didn't give good info please let me know what i should mention. Not a network guy.
Modem: ZXHN H168N V3.5
ISPName: MTS
1 LAN connection usually and now a 2nd one that's causing problems and 2-3 Wi-Fi connections usually (2 phones and a laptop, have been connected since forever, never caused issues)
I don't have any info about NAS
No additional Wi-Fi router, it's built into the modem
I'm using the LAN connection on my motherboard (Mortar MAX B450m and now, a Dell SFF 7010 1155 Motherboard)

So as i mentioned, i am not a network guy, like, at all. I'm good with building computers and messing around with the PC hardware side of things but not the network, a bit above basic level.
Recently, i wanted to connect a second PC to my network so i can have a LAN party with my neighbours so i bought a basic Ivy bridge PC that can run the stuff we need it to run, and set it all up, however, after i did that, the network became very unstable. At first it was fine but 2 days later it started to drop, randomly, at random times of day for random periods of time (Usually, even when just my main PC is connected which used to work fine, it'll be ok for 3,4 hours and then in a 30 minute span drop every 4,5 minutes for about 10s-1minute.) If i connect the 2nd LAN cable to a port, in any combination (There's 4 of them on the modem, i enabled all 4 atm on the localhost admin site because by default only 1 and 4 work for PCs (I tried all combos as well, no difference)) without fail, everytime, in about a couple minutes it starts to drop the connection, the LEDs on the modem all show no problem , and then after a while the modem restarts, and it just repeats the cycle. My ISP has a monopoly over my area(I live in a bit of a rural area so can't really get another ISP) and they just do not care to do anything about this, so i'm here asking, is there anything i myself can do to atleast figure out why the problem is happening, is it the cables(Although i tried different ones with the same result), is there a connection break somewhere on my end, or just something so i can either fix it myself or tell them the exact type of issue so i can request new gear or SOMETHING just so i don't have to fear doing anything that requires no internet breaks?

 

[bill001g]

What do you mean "lan party". Did you connect the network in your house to the neighbors or do they bring pc over to your house ? Or did you just buy a second pc that you let other people use when they visit.

It sound like there is some kind of IP conflict. Use the IPCONFIG /all command and look at the IP addresses and make sure they are not the same and they have the proper gateway/mask/dns etc.

The device you have is very common router and the 4 ports just act as a simple switch. If you truly are running just lan/lan connections the traffic does not even go to the router cpu chip it passes directly between the 2 lan ports on the device.

Does it actually crash the router or are manually resetting it and it clears your problem. Now this could be a generic issue where the extra traffic is killing you internet connection but you should see similar issues if you were to say download large files.

 

[ashdejan]

.

Oh, it's just a second PC in my house connected to my network via a LAN cable that they can use since they come over often. Sorry for the confusion.

Here's the info, the public IP, is the same for both(Like the one you can look up on google etc.); ipv4 are different in (.1.11 and .1.2); mask/gateway & dns are the same. Don't know really what i should look for/look out for. (I would just post the info but it said on the FAQ to be careful which parts we post when it comes to IP so i honestly am not sure what i can and can't share. Sorry if i sound like a noob, this really isn't my territory.)

Yeah it feels really cheap and flimsy but that's what i got when i signed up. It's just basic lan connections, standard stuff. So what's the move? Should i buy a new modem? Could that fix the issue? Sadly i don't have another one to test and see if it makes it better.

Ok, so the exact thing that happens(I usually have -ping -t 8.8.8.8 pulled up on my cmd to follow): So, i connect the 2nd LAN, and then about 5-20 minutes later> the requests get timed out on cmd first(Power,DSL,internet LEDs are on during that)>After about 30 seconds the DSL and internet LEDs turn off by themselves, i touch nothing(The same way as when you press the reset button, the power is on)>and then they just start blinking until DSL becomes a stable light and internet turns on and starts flickering as normal. And then it goes again.

No problem downloading big files/any files. No problem with using my main PC lan and 2,3 wifi connections to download files at the same time, when i connect the 2nd lan cable, it starts freaking out.

 

[bill001g]

The only IP that is somewhat a risk is the public IP. It is just not a good idea to tell people it but it is not a huge risk. The hackers scan every possible IP. Most times the problem is if someone dislikes you for some reason they can pay money to denial of service attack you. You see this mostly in online shooter games where someone gets offended for some reason if you were to say post is accidentally to this forum nobody really cares enough pay money to attack you.

So what I would try is to run a ping between the .1.11 and .1.2 IP. If you get loss here then something is very strange. This should work even if you were to unplug the wan/phone cable coming into the router. If this fails it could be a defective router but it is not very likely.

When the DSL and internet light goes out it generally means there is some issue with the connection coming to your house. It really should not matter if you have 1 machine or 10 plugged in you should get the same problem. It is hard to say what the second machine is doing. Just using the internet from the second machine should not have much effect. If it were say to download a large windows update you might get a little slowness on your main machine but the DSL connection should stay up.

Although the ISP will likely say everything is fine I would still call them and maybe you get lucky. I would not tell them anything about 2 machines etc. I would just tell them the DSL and internet light are going out. Maybe they can tell you how to see the logs in the router. Their equipment should also see the disconnect and reconnect so maybe write down the exact times it happens before you call them.

 

[gggplaya]

We used to have LAN parties back in college. But back then, half the people still had 56k modems, so LAN parties were more normal. Over 100 people would show up, we charge $20 a head, but that included pizza and red bull. Fun times! We played the original counter strike and Battlefield 1942.