Best mtu for draytek 166 with asus rt-ax86u

[hash70]

Jst bought a draytek 166 gen 2,only issue I'm having is what mtu size do I use,its setup in bridge mode with cat 6 to asus rtax86u connected via pppoe, the vigor mtu is set at 1520 out the box,im sure bt use 1492 so don't understand why it's at 1520,my asus rt-ax86u mtu is at 1492,can't go any higher,so should the vigor 166 and asus rt-ax86u have the exact same mtu 1492?

 

[ColinTaylor]

I would leave it as it is. You shouldn't really need to lower the MTU on the Vigor. The router will clamp the TCP MSS to the PMTU of the WAN interface for PPPoE connections anyway.

 

[hash70]

I'm not noticing any issues yet with the vigor mtu at 1520,a friend told me to set it at 1500 with my asus at 1492,it seemed to working fine all day streaming Netflix /browsing ext but I kept losing connection to the ps5 server while playing cod,changed it back to 1520 and connection is stable