Hi guys,
I asked this question in serverfault.com. but I didn't get answer. It is an example in openvpn cookbook. here is my toplogy:

here is my server config file:
proto udp
port 1194
dev tun
server 192.168.200.0 255.255.255.0
ca /etc/openvpn/cookbook/ca.crt
cert /etc/openvpn/cookbook/openvpnserver.crt
key /etc/openvpn/cookbook/openvpnserver.key
dh /etc/openvpn/cookbook/dh2048.pem
tls-auth /etc/openvpn/cookbook/ta.key 0
keepalive 10 60
push "route 192.168.4.0 255.255.255.0"
topology subnet
daemon
log-append /home/mazimi/Desktop/openvpn.log
client-config-dir /etc/openvpn/cookbook/clients
route 192.168.2.0 255.255.255.0 192.168.200.1
here is /etc/openvpn/cookbook/clients file:
iroute 192.168.2.0 255.255.255.0
here is my client config file:
client
proto udp
remote 192.168.3.1
port 1194
dev tun
ca /etc/openvpn/cookbook/ca.crt
cert /etc/openvpn/cookbook/client1.crt
key /etc/openvpn/cookbook/client1.key
tls-auth /etc/openvpn/cookbook/ta.key 1
daemon
log-append /root/openvpn.log
ns-cert-type server
This configuration is working fine. But why the next hop(In the server config file) is set to 192.168.200.1?(it is a local interface not next-hop). Shouldn't it be 192.168.200.2? actually I changed it to 192.168.200.2, and it is working too.