No ping from OpenVPN server to client, how to solve the problem?

Question

openvpn

Good night, there is a server on Debian 7, an openvpn server is raised on it, the ubuntu-desktop-14.04 client connects to it, pings go both ways, but when connecting from windows 7 prof x64 to the openvpn server, the ping goes only to the server, the client does not pinging, please help in this matter
PS The software versions are all fresh, today I installed everything, the brandmauer was also disabled on win 7, also according to this recommendation https://openvpn.net/index.php/open-source/faq/79-c ... exceptions were added to iptables
Thanks in advance
Server config:

port 1194
proto udp
dev tun
user openvpn
group openvpn
cd /etc/openvpn
persist-key
persist-tun
tls-server
tls-timeout 120
dh /etc/openvpn/dh.pem
ca /etc/openvpn/ca.crt
cert /etc/openvpn/vpn-server.crt
key /etc/openvpn/server.key
tls-auth /etc/openvpn/ta.key 0
server 10.15.0.0 255.255.255.0
client-config-dir /etc/openvpn/ccd
client-to-client
topology subnet
max-clients 5
push "dhcp-option DNS 10.15.0.1"
route 10.15.0.0 255.255.255.0
comp-lzo
keepalive 10 120
status /var/log/openvpn/openvpn-status.log 1
status-version 3
log-append /var/log/openvpn/openvpn-server.log
verb 3
mute 20
cipher AES-256-CBC
#мmultiple user connect with same keys and cers
duplicate-cn

Client config (windows)

dev tun
proto udp
remote aa.bb.cc.dd
port 1194
client
resolv-retry infinite
ca ca.crt
cert developer1.crt
key client.key
tls-auth ta.key 1
remote-cert-tls server
persist-key
persist-tun
comp-lzo
verb 3
status-version 3
cipher AES-256-CBC
auth-nocache