I have this interesting duplex mismatch problem and hope that someone can help me. I started to see these errros ever since I moved these hosts from CAt OS (4006) to Cat IOS (6500)
For example this error below says fa1/23 is NOT FULL DUPLEX but if you see the config below the port fas1/23 is hard coded to 100/full.
10:25:08.790: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet1/23 (not full duplex), with PCFE40PA FastEthernet0/1 (full duplex)
switchport access vlan 912
switchport mode access
no ip address
But here is the interesting part, when I do show int fas1/23, it says that is set to half-duplex and that's where I'm lost
FastEthernet1/23 is up, line protocol is up (connected)
Hardware is C6k 100Mb 802.3, address is 0005.5f28.c6ee (bia 0005.5f28.c6ee)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
I'm on Cisco 6506 with WS-SUP32P-GE runing 122-18.ZY2.bin. Line card in question is WS-X6348-RJ-45.