I look at IP/FIREWALL/CONNECTIONS and see that one client have over 1000 established connections at same time. Can I somehow limit user or group to 50 connections??
anybody knoes how can I limit connections in version 2.9?
Change syntax for 2.9 version, and try configuration like for 2.8.
in 2.9 be like this
add chain=forward protocol=tcp tcp-flags=syn connection-limit=100,32 action=drop comment="connection limit" disabled=no
this line is limiting tcp syn connections to 100 per ip i think
if i’m wrong then correct me 
So, how to limit the UDP connections?..
Uhmm… UDP is connection-less by design. There is no such thing as an “UDP connection” …
–Tom
sorry - you’re right of course 
… no matter how you call it 
, but I still cannot limit udp sessions…
See this discussion:
http://forum.mikrotik.com/t/when-connection-limit-for-udp/3076/1
–Tom
The problem of limiting connections is that if you have for example 50, and you have P2P programs you can use 50 connections for P2P and if you try to surf web or mail you cannot, because all possible connections are used by P2P.
So I think you have to mangle P2P packets and then limit connections to P2P packets.
Any suggestions or solution for this?
You can limit connections as said above and the limit you set can afect browsing if too low. I find around 70 - 100 is good.
There was a UDP connection limit patch available for IP Tables (Linux) I don’t know if MT is IP tables based of if they have done their own thing? But it is possible.