Why doesn't OpenVPN change client ip?

Question

openvpn

Hello!
Server config:

dev tap0
proto udp
mode server
comp-lzo
log-append /var/log/openvpn.log
daemon
ifconfig 10.8.0.0 255.255.255.0
tls-server
dh /etc/openvpn/dh1024.pem
ca /etc/openvpn/ca.crt
cert /etc/openvpn/server.crt
key /etc/openvpn/server.key
port 5000
user openvpn
persist-tun
persist-key
verb 0


tls-auth /etc/openvpn/ta.key 0
cipher DES-EDE3-CBC

Client config:

dev tap
proto udp
remote ip 5000
client
nobind
tls-client
comp-lzo
ns-cert-type server
ca ca.crt
cert user_pc.crt
key user_pc.key
ping 15
ping-restart 45
ping-timer-rem
persist-key
persist-tun
verb 1
tls-auth ta.key 1
cipher DES-EDE3-CBC

Why doesn't the ip change on the client?