hi
i use 100mbps connection,if i direct lan from modem to pc i get 90-100mbps.
but if i use this router it 's give me full speed just a few minutes and then speed dropped to 25mbps max. with many error ack flood bla..bla..bla. so i need to turn off modem and router for a few minutes to normalize my speed back to 100mbps.
-dir-605l
-v.2.08/any ,except 2.05UI
-b2
-asia region
-modem dassan h670g
i tried my friend's router other brand, its working like charm give me full speed anytime.
please dont ask me to turn on/off any setting or change some setting. trust me i already change the settings 1 by 1, but the problem is still persist.
i already search and install all firmware and then factory reset. only v.2.05ui work better. this version doesnt dropped my connection to 25mbps but 70mbps. but when i upgraded to other version with/without reset setting it will increase my speed to 100mbps for a few minutes then drop 25mbps. with error log ack flood icmp bla bla bla.. i think this error log is caused by my isp, they block any public dns. if i use dnscrypt or any proxy/vpn this will cause my internet immediately dropped to 25mbps even i already turn off vpn/dnscrypt. but not for 2.05ui, still stable at 70mbps

please give me good solution,or please make firmware rev based ver 2.05ui for increase speed. thank you!
nb: i connect just for 1 pc with LAN connection. i already connect with different pc but give me same problem. and ver 2.05ui cannot change bandwidth,only show 20mhz and greyed out. other firm ver able to change 20/40mhz.