I am struggling with weird problem many weeks, maybe it is not about MT, but I will try:
I have small LAN network - workstations with Win XP SP3, IP are assigned from DHCP on Mikrotik 4.13 (RB433) router, one Ubuntu/Samba server
connection to WAN is via MT src-nat
On random workstations with XP SP3 in a random time (aprox 3 times in a week, on each PC in a different time or day):
www and emails stop working on particular machine, all other services (ping, DNS translation, SKype, ICQ etc.) work OK
ipconfig /all shows correct values
route print shows correct values
from outside I can connect via dest-nat and VNC to this machine without any problem
connection to Ubuntu/Samba local server without any problem
on MT firewall no restrictions (I also tried first rule - allow all from such machine)
after PC reboot everything works fine immediatelly
I would expect some problem with Mikrotik settings, but I am using MT on many other places without any problem. If problem with computers, what kind? Looks no virus, no spyware on workstations … If I try to log traffic from problematic machine on MT firewall, no errors in a log. PCs have a different hardware.
Any idea?
Thanks
Ivan
It sounds like a machine issue to me more than anything else. Are you using IE and Outlook then? I would check the settings in IE, like that Automatic Detect Settings, proxy (if you don’t have one) and automatic startup scripts are disabled. Outlook uses IE to render stuff, so when IE stops working so does Outlook.
I would be curios to see if they downloaded Chrome or Firefox if they still had problems with those browsers when IE stops working.
Then I would check whatever firewall you have on the PCs and see if that is the problem, possibly turn it off for a day or two and see if the problem is still there.
Are you using a proxy or anything like that, or possibly have any queues on the router? How about any filter rules to drop packets from certain addresses? If you’re thinking it might be the router, you can always wipe the configuration and rebuild it to eliminate that as a potential source of a problem, you could even go as far as to do an netinstall to reformat the flash drive. But all the route does is route packets, if ping and DNS work, then HTTP and SMTP should work fine.