Hi Ronald - What version of code is it running on the switch? RADIUS CoA, SNMP, SNTP, Syslog, DHCP, IPsec, etc are some of the protocol that use UDP. If many of these services are enabled and have many concurrent sessions running at the same time, there's a chance that the switch could run out of memory reserved for UDP ports. I believe we made some enhancements to allocate more memory for UDP ports as well better session managements in newer releases. Please upgrade to the latest 8090 release if you haven't done so. If you still see the issue on latest 8090, please open a case with Support.