As mentioned in the first post. This how it looked after a fresh factory reset without any extra things and only one single device is connected. The average ping is between 50 and 100ms.
Then all the problems are gone. Ping: <1ms and high speed internet.
After factory reset (and setting for repeater):
root@GL-MT300N-V2:~# ifconfig
apcli0 Link encap:Ethernet HWaddr E6:95:6E:04:2E:B1
inet addr:192.168.100.9 Bcast:192.168.100.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
br-lan Link encap:Ethernet HWaddr E4:95:6E:44:2E:B1
inet addr:192.168.8.1 Bcast:192.168.8.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:437140 errors:0 dropped:0 overruns:0 frame:0
TX packets:523284 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:220815559 (210.5 MiB) TX bytes:560501101 (534.5 MiB)
eth0 Link encap:Ethernet HWaddr E4:95:6E:44:2E:B1
inet6 addr: fe80::e695:6eff:fe44:2eb1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:23192 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:3428961 (3.2 MiB)
Interrupt:5
eth0.1 Link encap:Ethernet HWaddr E4:95:6E:44:2E:B1
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:21732 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:2839332 (2.7 MiB)
eth0.2 Link encap:Ethernet HWaddr E4:95:6E:44:2E:B1
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:1446 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:494532 (482.9 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:934 errors:0 dropped:0 overruns:0 frame:0
TX packets:934 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:78289 (76.4 KiB) TX bytes:78289 (76.4 KiB)
ra0 Link encap:Ethernet HWaddr E4:95:6E:44:2E:B1
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:509659 errors:1674 dropped:0 overruns:0 frame:0
TX packets:550868 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:243888687 (232.5 MiB) TX bytes:559289261 (533.3 MiB)
Interrupt:6
Everything is changing constantly and it’s hard to reproduce. Sometimes i get average ping rates of 25ms (In rare occasions) to the MT300. Sometimes 300ms… and sometimes 50ms… (measured over an 1 minute time frame)
Sometimes i get speeds of only 2Mbps and sometimes 18Mbps. But always have a RSSI of >60dB.