On Linux, you can restart network service with command

# service network restart

Similar command is available for FreeBSD, but is less used/known.

The command is /etc/netstart

freebsd# /etc/netstart
hw.bus.devctl_disable: 1 -> 1
lo0: flags=8049 mtu 16384
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
inet 127.0.0.1 netmask 0xff000000
dhclient already running? (pid=238).
route: writing to routing socket: File exists
add net ::ffff:0.0.0.0: gateway ::1: File exists
route: writing to routing socket: File exists
add net ::0.0.0.0: gateway ::1: File exists
net.inet6.ip6.forwarding: 0 -> 0
net.inet6.ip6.accept_rtadv: 1 -> 1
route: writing to routing socket: File exists
add net fe80::: gateway ::1: File exists
route: writing to routing socket: File exists
add net ff02::: gateway ::1: File exists
IPv4 mapped IPv6 address support=NO
freebsd#