OPNsense Forum

English Forums => Hardware and Performance => Topic started by: senser on August 01, 2021, 10:30:45 pm

Title: Should MTU be the same for all NICs in the Router?
Post by: senser on August 01, 2021, 10:30:45 pm

So I have
LAN (default mtu 1500) <-> apu2 <-> pppoe dsl WAN (mtu 1492)
Should I set an mtu of 1492 on the LAN nic as well? Thanks!

Title: Re: Should MTU be the same for all NICs in the Router?
Post by: hushcoden on August 02, 2021, 01:12:59 pm

I set up my WAN port to 1500 - see attachment, but you need a modem which can support that, i.e. Draytek modems...

Title: Re: Should MTU be the same for all NICs in the Router?
Post by: chemlud on August 02, 2021, 02:15:15 pm

https://homenetworkgeek.com/mtu-size/

https://hide.me/en/knowledgebase/how-to-find-correct-mtu-values/

MTU field comment on WAN interface GUI tab says

"If you leave this field blank, the adapter's default MTU will be used. This is typically 1500 bytes but can vary in some circumstances. "

touch only if you have good reason.