tun missing

[sec13b]

When i start run openvpn-install.sh

bash openvpn.sh
TUN is not available

ls - l /dev/net

ls: cannot access -: No such file or directory
ls: cannot access l: No such file or directory
ls: cannot access /dev/net: No such file or directory

I try to create:

mkdir -p /dev/net
mknod /dev/net/tun c 10 200
chmod 600 /dev/net/tun

and start again to install , this work, but

ifconfig

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet xxx.xxx.xxx.173  netmask 255.255.255.128  broadcast 0.0.0.0
        inet6 fe80::64c0:5bff:fea0:b590  prefixlen 64  scopeid 0x20<link>
        ether 66:c0:5b:a0:b5:90  txqueuelen 1000  (Ethernet)
        RX packets 267042957  bytes 44993809169 (41.9 GiB)
        RX errors 0  dropped 3004963  overruns 0  frame 0
        TX packets 215122060  bytes 121474782783 (113.1 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.25.146.10  netmask 255.255.255.0  broadcast 10.25.146.255
        inet6 fe80::fceb:6cff:fe41:ac04  prefixlen 64  scopeid 0x20<link>
        ether fe:eb:6c:41:ac:04  txqueuelen 1000  (Ethernet)
        RX packets 869196425  bytes 159675110161 (148.7 GiB)
        RX errors 0  dropped 3030152  overruns 0  frame 0
        TX packets 939415471  bytes 80779200685 (75.2 GiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 17556  bytes 7774069 (7.4 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 17556  bytes 7774069 (7.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

any help