Hello!
Sorry, for my bad english.

I have problem.
I have RB2011L-RM, MIkrotik version 6.15, all run is ok, BUT sometimes i can't connect remotely via SSH or Winbox, wherein it works: forwarding ports, filters firewall, NAT etc.
Access is restored after a reboot(off/on power).

What could be the solutions to the problem?

Thank!

Insufficient data.

Insufficient data.

All services are installed in the router work.
Forwarding port (dst-nat on different port) - i can connect to inside servers.
I have response on ping its ip-address.
But when i try to connect from the outside to the router via ssh or winbox nothing happens.
SSH - timeout connection
winbox - simple wait
After reboot power(off/on) i can connect to the router.

Happened, that DNS download CPU 100%
(looking 'System -> Profile')

Do you have a serial console that you could attempt to connect to? Check maybe you can use that to get to the router.

Do you have a serial console that you could attempt to connect to? Check maybe you can use that to get to the router.

Unfortunately there is no serial port.

i even connect to the inside server via RDP-protocol and tried connect to the router(RB2011) by MAC-address - unsuccessfully.
Ping to MAC response.

Maybe your UDP/53 port is open and you're getting queries from outside your network. Put some firewall rules or disable the service completely if you're using an external DNS server for that network.

Maybe your UDP/53 port is open and you're getting queries from outside your network. Put some firewall rules or disable the service completely if you're using an external DNS server for that network.

For outside network 53 port(DNS) is closed. Will observe...