can't login modem/router

[likertuban]

so i have an internet with around 7-8 people used it (internet on boarding house).
i use modem TP-link TD-w8151n :

usually i can login on 192.168.1.1,
but there's someone with a certain MAC address, if that one connect to my internet, suddenly 192.168.1.1 is not accessible,
i can still ping 192.168.1.1 normally, and the ping did say 1ms or <1ms.
but if i ever try to type 192.168.1.1 on the browser, and hit enter, it's only loading, if i waited so long, it say loading error, kind of RTO,
i can access and login again after restarting the modem, and when i block that MAC address using MAC filter setting on router, if that person, not connected. i always be able to login on the modem.
but once i release that mac from mac filter, i can't access modem anymore :3

is there someone know what the heck happened to my modem/router?
did someone inject it with something, or there's a virus that may cause it? o.O

for your information, sadly, i can't check the user's computer one by one. and there's no way i'm allowed to block that mac forever since they pay the internet monthly together :3

sorry if i may mistaken about modem or router
and sorry for my bad english.
hope someone can give an answer.

[MentaL]

[Monolith]

Some modems and routers only allow one person to be logged into a settings page at once....maybe the person that has that mac address is logging into it just to mess with you....did you try changing the password?

[Matynator]

so i have an internet with around 7-8 people used it (internet on boarding house).
i use modem TP-link TD-w8151n :

usually i can login on 192.168.1.1,
but there's someone with a certain MAC address, if that one connect to my internet, suddenly 192.168.1.1 is not accessible,
i can still ping 192.168.1.1 normally, and the ping did say 1ms or <1ms.
but if i ever try to type 192.168.1.1 on the browser, and hit enter, it's only loading, if i waited so long, it say loading error, kind of RTO,
i can access and login again after restarting the modem, and when i block that MAC address using MAC filter setting on router, if that person, not connected. i always be able to login on the modem.
but once i release that mac from mac filter, i can't access modem anymore :3

is there someone know what the heck happened to my modem/router?
did someone inject it with something, or there's a virus that may cause it? o.O

for your information, sadly, i can't check the user's computer one by one. and there's no way i'm allowed to block that mac forever since they pay the internet monthly together :3

sorry if i may mistaken about modem or router
and sorry for my bad english.
hope someone can give an answer.

look at what the settings are at.. then why not try to reset it to factory default see if it works better..
if not.. just put the settings back as they belong ;)

also make sure everyone's adapter settings are on non-static.. that might solve some problems.. the router should be the dhcp provider..

[likertuban]

Some modems and routers only allow one person to be logged into a settings page at once....maybe the person that has that mac address is logging into it just to mess with you....did you try changing the password?

i already change the password, and i turned off the multiple account system, so only admin account can login, and only me who knows the password.

look at what the settings are at.. then why not try to reset it to factory default see if it works better..
if not.. just put the settings back as they belong ;)

also make sure everyone's adapter settings are on non-static.. that might solve some problems.. the router should be the dhcp provider..

been resetting to default and custom setting multiple time,
same result,

when he is connected, i won't be able to enter the modem, even after he is not connected anymore, i still can not to login, till i restart (turn off and turn it on) again.

[bugme]

I saw something that there's a hole on the back of the router where you can stick a toothpick in, basically when you do that the router will reset. If that works then you're probably able to log in either with the default password or no password at all, because if it doesn't have any passwords then you're able to log in and set your own password.