Strange problem with network

RouterOS General
1

I use MikrotikOS 2.9 for my wireless network as central point. It has 2 wlan cards i 1 ether. Mikrotik is set to be just a AP (2 AP’s to be exact) and bridge between these 3 interfaces.
Problem is that when I try to copy some thing from another computer which is connected over wireless, connection brakes down at middle of copying. First I thought that wireless connection with that client brakes down but then I realized that I lost connection with ONLY that computer.
For example there is client (AP in client mod) connected to Mikrotik with few computers on switch in his own network and when I lose connection with one of them while trying to copy it is ONLY with that computer from which I tried to copy, other from that network I can see and access with no problems.
It’s like Mikrotik block access only to that IP. When I try pinging that computer I got 100% lost packet but that block is only for me because others in network at the same time can see that computer and access him. After that I have to wait for few minutes to access that computer again. This phantom problem occur not only to me but to everyone in network who try to copy some thing and traffic goes through Mikrotik.

Sorry for amount of text but it’s hard to explain what happens in just few words.

2

What signal strength are you getting on the wireless connections? Are you trying to use encryption on your wireless links? Try disabling encryption.

I’ve seen this kind of problem before where signal strength is poor and you’re trying to use encryption. PING works OK because by default they’re small packet sizes, but when you try to transfer a large file the packet sizes increase and you get failures.

The other thing to check is that you haven’t get any duplicated IP or MAC addresses.

3

Signal strength is very good about -61 to -69 dBm. Clients in shows signal strength about 70-90%

And we dont use any encription.

I don’t think problem is in wireless connections. It must be something else