Cosmote modem to Asus router recent problems

[DJBLUELADY]

Hello
I have problem to connect RT-AX1800U router on Cosmote Greece ISP. 
6 months earlier I connect one more expensive Asus router (RT-AX86S) with Cosmote speedstar modem and standard installation 
procedure passed normally and it functioned OK. But after 
3 to 4 months it stop to work in way to do not want to go on internet and start to choke modem so I had do disconnect router and restart modem. 
I had in my mind router is defected and buy new RT-AS1800U. But he work or not work in 
same manner loike previous. I see modem try installation , it passed, but router do not want to connect on modem and go on 
internet. I try and DHCP and PPPOE connection but both do not work in same way. I think Cosmote someting change but cannot 
get their support to check. Maybe I have to instal some modem mode which Asus offer during installation but do not know.
Does anybody have something in mind so can help me?
ISP modem adress is 192.168.1.1
Router address is 192.168.50.1
Earlier when istalation run and everything worked my SSID had router address 192.168.50.X
Now ti does not work with describe standard procedure.
Br Dusko

[trendy]

Zdravo Dusko,

It may as well be the issue from your modem.

Have you tried to connect your pc directly on the modem and see if it will work with DHCP or PPPoE?

Usually if the modem in properly in passthrough mode, then the router behind it should work with PPPoE, otherwise the router will get settings from DHCP but you'll have double NAT there.

[fatalara]

Τι έγινε γίναμε Ιντερνασιονάλ;

[trendy]

Απεξαπανέκαθεν!

[minast]

If you run the connection wizard, try setting VLAN ID to 835.

After the initial config, you should find this setting under LAN-IPTV. Set Internet VID to 835 and see if it works.

[DJBLUELADY]

On 9/18/2023 at 11:22 AM, το μέλος trendy έγραψε:

Hi Dusko,

It may as well be the issue from your modem.

Have you tried to connect your pc directly on the modem and see if it will work with DHCP or PPPoE?

Usually if the modem is properly in passthrough mode, then the router behind it should work with PPPoE, otherwise the router will get settings from DHCP but you'll have double NAT there.

Thasnks , both modem was brand new. No matter old one will come from reclamation tomorrow  and will see does it work or not and let you know.