I have 400-500 sessions online, Mikrotik 5-6 days work and at calling on it through winbox shows nothing. Authorisation at users does not accept!!! The problem after reboot only dares. At my friends online 1000-1500 same problem, we wish to pass on mpd.
System
Quad 3.0
Asus P5-KPL
Intel pro 1000
HDD Transend DOM (flash ide)
Founders Mikrotik when you will correct this problem???
what’s your summary traffic through that router?
The problem is not in PPTP 
You are using MAC address to connect, this connection is VERY slow, so Winbox simply can’t show you everything. Use IP to connect and all will be fine.
My users cannot incorporate with VPN a server! Only after reboot the server starts to work!
Problem not in winbox.exe, I incorporate to the address instead of on MAC
Are you using RADIUS for authentication ?
yes radius
And do using PCQ ?
There is an old bug in mikrotik at radius client which causes some big problems like yours but mikrotik hardly defends against it and did not confirm that .
The bug is not in pptp server . it is in mikrotik radius client . look at radius client timeouts . you will see a lot of timeouts there . when radius client freezes , the interfaces hide , routing will have problem , users could not authenticate , sometime snmp breaks , and many many more problems . i am following this problem in this topic http://forum.mikrotik.com/t/routeros-radius-client-timeout-pppoe-pcq/34479/1
Why founders do not correct an error my friends wrote to them concerning this problem.
to fix an error, one should first locate it and identify =)
This problem has been identified by mikrotik developers since early versions of 3.x . i have those ticket numbers . first they said it is a kernel bug . after several months they said the kernel upgraded but now the version is 4.5 and still the problem is there .
To Chupaka : You are an advance user and helping many peoples to solve their problems . but i have seen in some posts that if a problem did not occur for you , you some times bypass it or defend against it or just kidding about it . i think mikrotik guys will hear from you better than new users . so please help to solve problems which did not occur for you . maybe sometimes it also crash your router =)
actually, we’re using v3.28 on our pptp server, and I have a ticket (from Jan, 2009) about memory leak - seems like it’s for sure in pptp server (we have a router with almost the same config, but w/o pptp server - and it works fine). here’s graphing for memory:
each leap down is router reboot (crash =) ), and huge packet loss a few minutes before. as I can see, 3.28 have less memory leak than earlier, and I dream about a day I upgrade to v4 and continue writing to support if problem persists