Strange one, we have a small LAN in a regional office with a 48 port 2960. On that switch we have 2 copiers/printers, one is HP one is Xeriox. Most users can print fine, but there are 4 PC that suddenly can't and they can't ping the printers either.
I ran wireshark and it sends out an arp request, but nothing comes back. I can ping the printers fine over the WAN. We've restarted the PC's and copiers/printers with no success. On the switch the ports show no errors or duplex issues, as I said this was working. What is strange these PC's cannot ping the CCTV equipment either, but many others are fine and can.
What is strange again is when I ping the copier 172.30.14.10 it doesn't say request timed out, but reply from <IP of PC> destination unreachable?
The switch has 2 VLANs 1 for voice and one for data and the are 2 routers in HSRP, which are running in as a router on a stick with sub interfaces.
The switch can ping the copiers. When I pinged 172.30.14.0 all the live IPs came back but not the copier or printer.
Saw this message to, I upgraded the firmware weeks ago though:
Mar 10 18:47:43.318: %ILET-1-AUTHENTICATION_FAIL: This Switch may not have been manufactured by Cisco or with Cisco's authorization. This product may contain software that was copied in violation of Cisco's license terms. If your use of this product is the cause of a support issue, Cisco may deny operation of the product, support under your warranty or under a Cisco technical support program such as Smartnet. Please contact Cisco's Technical Assistance Center for more information.