Ошибка PLATFORM_UCAST-4-PREFIX Catalsyt 3750

show platform tcam utilization
sh platform ip unicast counts
sh platform ip unicast failed route 

Тут подробно - http://www.anticisco.ru/forum/viewtopic.php?f=2&t=4836&view=previous

Тут же мимо ходом. Нашел процесс, который съедает весь цпу. HL3U bkgrd process. По нему нашел вот что - https://supportforums.cisco.com/discussion/11788206/hl3u-bkgrd-proce-high-cpu-usage-3750x-switch:

Hl3u bkgrd process - manages quite a few background tasks like

- Hardware Arp throttling house keeping tasks

- Retry adjs/Fib in case of an out of hardware resource condition

- proxy arp house keeping functions

- ICMP redirect processing

- TTL ICMP error generation in some conditions

- handling correct route forwarding in an output acl full condition

2) Check for ARP statictics under sh ip traffic.I dont have any access to the config of your device hence assuming.

could you check if "no ip arp incomplete enable" command dose the trick for you?

3) Also consider the bug mentioned by Alex thats a clean hit.