RT-AC5300 FTTH 1 GIG Speed issue


New Around Here
Hello Fellow SNBers

I Have a RT-AC5300 connected to fiber 1 gig and recently changed the ISP modem to new one that supports bridge mode as the old one didnt and now the PPPOE is on the AC5300 however on this new setup i am getting only around 600 mbits instead of the 1000 is used to get on the old modem noting that my connection is hardwire CAT6a and dont have any QOS or other services enabled on the asus :

- NAT Acceleration (Auto) CTF (Cut Through Forwarding) is enabled.
-Jumbo Frame (disabled)
-Spanning-Tree Protocol (Enable)

So is it a hardware limitation form the AC5300 ? since its now doing the PPPOE instead of the modem ? or a config issue from the side of the ISP or the modem (NOKIA ONT)

Any help is much appreciated



Very Senior Member
How are you testing the speed? From the router's GUI or from a wired computer connected direct to the router? On some Asus routers the GUI's speed test will report approximately half speed compared to a speed result from a computer wired to the router. Make sure to connect the router direct to the ONT no adapters or extenders in between.

Do you have, or have you ever had, AiProtection enabled? If so in addition to disabling it you also should check and withdraw from it on the Administration > Privacy page. Failure to withdraw may have an impact on router operation.


New Around Here
Router is connected directly to the ISP Modem/ ONT through CAT6a cable , never had Aiprotection enabled or anything else also just checked the privacy settings and nothing there , I use speed test on my Wired Pc also tried different laptops and macs all hardwired as i dont use the Wifi on Asus and still cant get over the 600 ish Mbits .

I bought a UDR (unifi dream router) but I know the UDR wont achieve the 1 gig as per Unifi community forms but that's for another thread soon and i still havent done the setup yet

maybe some one with same model and 1 gig can try ?

I am running asswrt - merlin latest


New Around Here
will changing the MTU value affect the speed its currently set 1492 and the WAN connection type is PPPOE also jumbo frame is disabled , that same settings are also in the ISP modem and i can change anything i want on the modem since they gave me the super admin user and passowrd but I am no network guru

I would appreciate any feedback from anyone with enough experince in ONTs and fiber connections too


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