To set the speed and duplex for a network card (NIC) on a FreeBSD system, you can use the ifconfig command with the media option. The ifconfig command is a utility for configuring network interfaces on Unix-like systems, including FreeBSD.
For example, to set the speed and duplex for the em0 network interface to 100 Mbps and full duplex, you can use the ifconfig command like this:
ifconfig em0 media 100baseTX mediaopt full-duplex
This will set the speed and duplex for the em0 interface to 100 Mbps and full duplex.
To set the speed and duplex for the em0 interface to 1000 Mbps (1 Gbps) and full duplex, you can use the ifconfig command like this:
ifconfig em0 media 1000baseTX mediaopt full-duplex
This will set the speed and duplex for the em0 interface to 1000 Mbps and full duplex.
To set the speed and duplex for the em0 interface to 100 Mbps and half duplex, you can use the ifconfig command like this:
ifconfig em0 media 100baseTX mediaopt half-duplex
This will set the speed and duplex for the em0 interface to 100 Mbps and half duplex.
Keep in mind that the ifconfig command only sets the speed and duplex temporarily. To make the changes persistent across reboots, you will need to add the ifconfig command to a startup script or configure the interface settings in the system configuration files.