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I recently moved into a room in a dormitory. This room has a wired internet connection.
The problem is that when I plug the cable into my laptop (HP Pavilion g15) it doesn't detect anything, it is like there is no cable and I tried everything from changing the cable to trying my laptop in another room.
It is actually a problem in the whole building, some students can connect, others can't. My friend's laptop can connect to the network using my room's connection.
My question is : Can the ISP block a connection so that the laptop can't even detect the network ?
UPDATE : -When I said "like there is no cable", I meant literally, windows doesn't detect that there is an ethernet cable connected.
-I tried all possible scenarios (changing the cable, connecting my laptop in a different room,etc) but nothing worked, it seems that the network allows some laptop to connect from any room and denies other laptops access also from all rooms. I also made sure that my ethernet port is working by connecting it to a router.
-There is no registration process to get access, you just insert the cable.
-I had already notified the housing office with the issue and they contacted the ISP, they have been trying to solve the issue for 3 weeks now and I really don't know why it is that difficult for them.
UPDATE : It has been a year and I almost forgot about this question but here is what happened next in case someone is interested :
The issue persisted for about a month, some laptops were able to access the network from all rooms (i.e. wall plugs), other laptops can't even detect it also from all rooms.
I contacted the people in charge in the dorms but they were extraordinarily slow so I had to do something on my own. I bought a small Wifi repeater, plugged the Ethernet cable into it and it worked right away with no extra config.
After a week or two some IT guys came to the building and installed routers in all the rooms (even for those who had no problem connecting). These were regular routers and they installed it just as I installed the repeater (which I took back to the store).
No one knew what was the original problem. I think they even decided to install the routers because they didn't know what was wrong. The single most strangest internet problem that happened to me.
12The ISP won't (And probably can't), be blocking anything that leads some computers to have the internet and some not. – barlop – 2018-03-18T23:41:58.393
1You might be able to do some more troubleshooting about which laptops can connect and from which connection points. You could also experiment with long cat5 cables – barlop – 2018-03-18T23:42:42.987
2Does your friend use the same cable in the same position in the same wall plug, and they have internet access while you don't? Does your friend's computer have a static address, or gets one through DHCP right away? Does your laptop work with the same cable connected to something, else like a router? Try plugging a router into the lan cable and see if it has access/gets an address, then to your computer (wired or wirelessly)? – Xen2050 – 2018-03-19T01:30:15.507
7@barlop an ISP (his campus absolutely can block some computers from accessing the internet and/or LAN – Keltari – 2018-03-19T05:28:58.857
2@Keltari You wrote " an ISP (his campus absolutely can block " <-- An ISP is different from the campus / team that runs the university's router(s). – barlop – 2018-03-19T05:37:53.237
Do they require you to use any proprietary software to connect, or to change the configuration? What OS are you using? – Chris H – 2018-03-19T09:10:19.607
1When you say 'it is like there is no cable', can we take that literally? The machine is telling you specifically that the network cable is unplugged? What happens if you force it to 100Mbps rather than leaving it on auto-negotiate? I ask because Gb ethernet requires that all 4 pairs are working correctly, whereas 100Mbps only requires 2, so it's possible to have a cabling problem that leaves a 100M connection working fine but a 1G connection believing that there is nothing there. – Nye – 2018-03-19T12:28:05.563
1@barlop, an ISP is the entity in charge of providing you access to the internet. The guys you call when you can't reach the web. If I provide a jack to my neighbor so that they can access the net, I am their ISP, as there is no way for them to call my ISP when the internet is down. Here, the campus is the ISP, and it is not unlikely for a campus to physically disconnect jacks to restrict access to the net, as opposed to a typical residential ISP that may simply blacklist the serial number of your equipment. – sleblanc – 2018-03-19T12:43:53.150
If the university blocked you from connecting then they should have either called you or sent you an email to let you know that they found illegal activity and have blocked you from the network pending completion of steps to fix the issue, remove illegal programs, downloads, promise you won't ever do it again etc etc. – Robby1212 – 2018-03-19T12:55:23.877
I'm suspecting that the DHCP has issued all available IP addresses, but testing for that from your location(s) will be difficult (because DHCP leases are kept for some time, etc). – Jan Doggen – 2018-03-19T13:33:50.617
Ask your colleagues or university for (what I suspect is required) an
eduroam
certificate – loa_in_ – 2018-03-19T15:26:32.917Can YOU connect to the network in another room using the cable? – PeteCon – 2018-03-19T15:43:43.707
Sounds like the DHCP-server has run out of leases. – Thorbjørn Ravn Andersen – 2018-03-19T17:12:39.137
Umm... I'm presuming this is a wall socket... "it doesn't detect anything, it is like there is no cable" are you sure that port is live? Have you talked with the provider to see if they have it patched, etc...? – Attie – 2018-03-19T18:50:35.043
1@sleblanc I haven't heard the term ISP used that way to even include the neighbour being the ISP if they give their neighbour access. From a technical perspective, the term used that way doesn't seem that useful. – barlop – 2018-03-19T20:17:32.460
I have ran into this issue before, it was the cable runs were too long or the cable was low quality and some network cards had trouble determining if there was a physical link or negotiating link speed, but some were ok (mostly intel cards) – Richie Frame – 2018-03-20T00:36:57.213
@sleblanc sorry but that's incorrect. "ISP" is a well-established term in IT lingo and we can't simply broaden it for philosophical reasons. An ISP manages the backbone connection and a "network manager" handles connecting clients within an orgination to the ISP. – None – 2018-03-20T04:04:52.293
@user30031 Wouldn't your definition limit ISPs to Tier 1? Often entities we call ISPs are Tier 2 or Tier 3 (especially outside US). – Maciej Piechotka – 2018-03-20T05:02:36.853
Is there the possibility that the computer's LAN interface has simply broken? Does it work with a different network at all or do other computers work on this network? – xji – 2018-04-03T22:18:17.110