Вот конфиг клиента:
client
proto udp
dev tun
ca ca.crt
dh dh2048.pem
cert oche_sekretniy.crt
key oche_sekretniy.key
remote x.x.x.x 1194
cipher AES-256-CBC
verb 3
mute 10
keepalive 5 15
persist-key
persist-tun
float
resolv-retry infinite
nobind
user nobody
group nogroup
tun-mtu 1450
И /etc/network/intefaces:
# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback
auto etc0
mtu 1450
auto tun0
mtu 1450