(M4250-26G4XF-PoE+)>enable
(M4250-26G4XF-PoE+)#configure terminal 
(M4250-26G4XF-PoE+)(Config)#interface 0/29
(M4250-26G4XF-PoE+)(Interface 0/29)#speed ?
10            Set speed to '10 Mbps'.
100           Set speed to '100 Mbps'.
1000          Set speed to '1000 Mbps'.
10G           Set speed to '10G'.
auto          Enables/Disables automatic negotiation on a port.

(M4250-26G4XF-PoE+)(Interface 0/29)#speed 1000 ?
full-duplex     Set to full duplex.
half-duplex     Set to half duplex.

(M4250-26G4XF-PoE+)(Interface 0/29)#speed 1000 full-duplex 
(M4250-26G4XF-PoE+)(Interface 0/29)#exit 
(M4250-26G4XF-PoE+)(Config)#