Disable resolving (?) requests in OpenVPN?

Question

openvpn

I'm not sure that the problem is in the "resolving" in OpenVPN, I'll explain with the example below.

Multi-threaded parser (PHP) downloads favicons on sites X 250 threads everything works from under VPN.

Accidentally forgot to disable proxy in the script and noticed the following:

1) Server (directly) x 250 threads = ~ 12 Mbps channel load (everything OK)
2) Server >>>> VPN (on) >>>> 3proxy (on) x 250 streams = ~ 12 Mbps channel load (everything is OK)
3) Server >>>> VPN (on) x

250 streams = 0.8 Mbps ( and file_get_content errors fly out)
In the 3rd case, I suppose vpn resolves each of my links. Tell me what to fix so that the work is correct in this case.

dev tun
fast-io
persist-key
persist-tun
reneg-sec 0
#nobind

remote moscow.vpnsite.com 1195
remote kiev.vpnsite.com 1195
remote minsk.vpnsite.com 1195

remote-random

local xxx.xxx.xxx.xxx
lport 11194

script-security 2
up /root/up.sh

ping 15
ping-restart 45

remote-random
pull
comp-lzo no
tls-client
verify-x509-name Server name-prefix
ns-cert-type server
key-direction 1
route-method exe
route-delay 2
tun-mtu 1500
fragment 1300
mssfix 1200
verb 3
cipher AES-256-CBC
keysize 256
auth SHA512
sndbuf 524288
rcvbuf 524288
auth-user-pass /root/pass.txt

<cert>
-----BEGIN CERTIFICATE-----
......................................