[Users] UDP traffic doesn't arrive in VPS

[Arjan Schrijver]

Hello people,

I've got a problem with my OpenVZ installation. We wanted to build a
syslog server on a VPS, but it looks like OpenVZ can't handle the UDP
traffic that arrives at the VPS.
When we have 3 or less servers logging to the VPS, everything works like
a charm. But when more (mail-) servers start logging, the UDP buffer
seems to overflow.
I looked at /proc/user_beancounters on the hardware node, and there were
no errors in the dgramrcvbuf line (or any other line). The buffer just
seems to fill until about 300000 (the limit is 1500000). The buffer
never gets above 300000, but most of the loglines don't arrive in the VPS.
Is there a limit on UDP traffic one VPS can receive?

Thanks in advance.
Regards,
Arjan