WS-C4507R+E - Duplex mismatch with MAC 1 (half duplex)

[Pear11]

: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet2/25 (not half duplex), with MAC 1 (half duplex)

: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet2/25 (not half duplex), with MAC t 1 (half duplex).
: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on GigabitEthernet2/25 (not half duplex), with MAC address Port 1 (half duplex).

Getting above log message, Cisco IP phone connected to switch WS-C4507R+E. 

Please advice on resolve the issue.

Thanks,

[Mark Malone]

Hi
whats connected to the g2/25 , please post show int g2/25, what is MAC 1 , is that only capable of half duplex ?
one side is set to half duplex ,you should match them both sides , full duplex preferably

speed 1000
duplex full

or if only 100mb
speed 100
duplex full

[Jaderson Pessoa]

Hello,

Maybe it is a cable problem. try swap the cable plugged on this device.

[Pear11]

Many phones has the same issue which is connected to same model 

[Jaderson Pessoa]

could you provide a configuration from this port?

[cmarva]

are you sure that someone does not have a hub plugged into the wall, and the phone plugged into the hub? That's my suspicion as I've not seen this symptom if a phone is plugged directly into the switchport. To me, this reeks of a hub in between.