Mtu change doesnt work on 386.11 via connection automatic ip.

[luzumsuz]

On my rt-ac86u 386.11 firmware router connected to docsis modem with mtu 1500.When i change it to anything it doesnt work.

 

[drinkingbird]

On my rt-ac86u 386.11 firmware router connected to docsis modem with mtu 1500.When i change it to anything it doesnt work.

Can you be a bit more clear? Are you decreasing the MTU due to ISP requirements? Do you reboot the router after? What "doesn't work"?

 

[luzumsuz]

İ want to use 1452 mtu for least overhead and also my line quality not good maybe this can be better for me i dont know.But changing mtu doesnt work on my unit.

 

[drinkingbird]

İ want to use 1452 mtu for least overhead and also my line quality not good maybe this can be better for me i dont know.But changing mtu doesnt work on my unit.

Have you determined the MTU of your ISP by doing ping testing? Where did 1452 come from? MTU will not fix "line quality" issues only issues with packet fragmentation if your ISP uses PPPoE or otherwise doesn't support standard 1500 MTU. If your ISP supports 1500 lowering it will only hurt, not help.

If you've found it needs to be 1452, Set the WAN MTU to 1452, hit apply, wait for it to finish, then reboot the router.

What do you mean by "doesn't work"? It changes back to 1500, connectivity doesn't work at all, etc?

 

[RMerlin]

Works for me.

admin@rtac66b1:/tmp/home/root# ifconfig eth0 | grep MTU
          UP BROADCAST RUNNING MULTICAST  MTU:1452  Metric:1