FreeBSD commands to set/check MTU

Here are various methods to change interface/ip interface MTU on current FreeBSD distros:

# ifconfig {interface-name} {ip-address} mtu 9000

# route change {ip-address/mask} -mtu 9000

To see the current MTU settings:

# route get {destination-IP-address} / ifconfig {interface-name}

Output:

route get 10.20.110.2
   route to: 10.20.110.2
destination: 10.20.110.0
       mask: 255.255.255.192
  interface: em0
      flags: <up,done,cloning>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      9000   -454924