Hi,
A discard can occur because a packet was sent to a TCP/UDP port for which there was no listener. For example, if someone tried to make a telnet connection to the IP address on the VLAN interface, but telnet was disabled.
A discard can be caused by a lot of different things. Usually, a discard is when a packet is thrown away. It can be thrown away because it ran out of buffers, the packet is corrupt, the wrong size.
One reason for receive discards on a switch is mismatched VLANs.W
Check the Configured VLANs on each switch port. The port with the RX discards will be "missing" a VLAN as compared to the other end of the trunk. The switch just "discards" the packets arriving on the missing VLAN.
Once the VLANs were matched up, the discards stopped.
Hope It helps.
Regards
