Hacking My internet is hacked by the neighbor

[Tomato123]

It would be best to try figure out how they got in in the first place. Realistically, I see these being the main possibilities:
1. Password being too short and able to be bruteforced after capturing the auth handshake.
2. Using an encryption method which is insufficient such as WEP or WPA1 (Not common anymore but still some use it).
3. WPS Pixie dust attack (Not common anymore but still some routers are vulnerable).
4. Physically retriving the password via social engineering or some similar method.
5. Something completely different is happening and it's not that guy doing it. Routers are pretty much directly connected to the internet and so it's not impossible for someone to be remotely running exploits on it.

Don't want to make it seem like I don't trust your word on that guy being the one doing it as I don't know him, yet I do know that computer engineer ≠ hacker. They are very different fields of knowledge which require many hours of learning/practice each.

 

[toolazytosearchitmyself]

Get familiar with your router. Use Mac address filtering. Check the device list to see what devices are connected. Take note and block those devices. Change your SSID. Change your password. Set upload and download limits if the guy keeps connecting. These are some things you could do

As already mentioned above, his neighbour can very easily spoof his PC's MAC address to match one on a whitelist. Without more details from the OP, there's not much we can do to help him.

 

[Desconocido90]

Sumarizing this thread:

• Factory Reset (or replace it entirely)
• >30 characters different passwords for Wifi and router. Length is more important that special characters, although adding some will protect the password from dictionary attacks. If the hacker has access to your router configuration, every measure here will be useless
• Wifi algorithm: WPA2+AES (probably it's already selected)
• Disable WPS (probably it's already disabled)
• White list MAC filtering would only work against extremely inexperienced hackers (script kiddies).
• Limiting the number of connected devices on the router might help to get him out, or at least annoy him.

I can think in a few more suggestions:

• If there's a firmware update for your router, install it (it might patch vulnerabilities). If it has unpatched vulnerability, replace it.
• Shut down the router when you're not using it. It's inconvenient, but also for the hacker, who could only hack it again during the periods of use.
• If you're using a PC relatively close to the router, connect to it by Ethernet and disable the Wifi.
• A crazy idea: reduce the reach of the wifi (removing the antenna or covering it up with aluminum) to the minimum degree you can live with, so the signal will be too weak to be usable for your neighbor.
• Another silly idea: Enforce a (non-porn, non-piracy) DNS plus a parental filtering in the router preferences. If he's going to keep stealing your wifi, at least he won't be able to have much fun.

Maybe the key is annoying your hacker enough for him to look for another victim, a more convinient wifi network to hack.

 

[Maximumbeans]

Are you sure your neighbour is on it?

 

[hippy dave]

Put shit (your own feces) through his letterbox every day until he stops using it.

 

[PewnyPL]

It may had been mentioned, but if you have WPS enabled (the thing that allows you to connect easily by ussing a button on the router) disable it.
Aside from the button, it also uses a short 8 digit PIN code. And that is painfully easy to crack.

If you are using WPA2 you could also try figuring out how to use WPA2-Enterprise and RADIUS if your router supports it, but that may not be that easy to setup.