forticlientsslvpn doesn't work with a proxy on Cent OS 7 - linux

Question

I'd like to use forticlientsslvpn on Cent OS 7 through a proxy but it doesn't work with a message "Can not connect to proxy" or "Can not resolve proxy address". I guess it needs some dependent libraries but I don't know them.
I downloaded the latest Forticlient SSLVPN 4.4.2329-1 64bit from here. (I installed it on debian then copied the forlder(/opt/forticlientsslvon) to the clean Cent OS 7.)
Both forticlientsslvpn CLI and GUI failed on the same error. This is the result of the cli command.
[root#cent7 /]# cd ~/forticlient-sslvpn/64bit/
[root#cent7 /]# ./forticlientsslvpn_cli --proxy 10.0.0.73:3128 --server 203.0.113.1:10443 --vpnuser myuser
Password for VPN:
STATUS::Setting up the tunnel
STATUS::Connecting...
NOTICE::Can not connect to proxy.
STATUS::Set up tunnel failed
SSLVPN down unexpectedly with error:2
Press Ctrl-C to quit
Clean up...
# Another proxy variable
[root#cent7 /]# ./forticlientsslvpn_cli --proxy http://10.0.0.73:3128 --server 172.17.97.85:10443 --vpnuser myuser
Password for VPN:
08/19/2016 18:19:26 [23461] can not resolve name http://10.0.0.73
Init SSLVPN error:Can not resolve proxy address
# Check the proxy connection
[root#cent7 /]# telnet 10.0.0.73 3128
Trying 10.0.0.73...
Connected to 10.0.0.73.
Escape character is '^]'. # OK
# Check DNS
[root#cent7 /]# nslookup 10.0.0.73
Server: 10.0.0.70
Address: 10.0.0.70#53
Non-authoritative answer:
73.0.0.10.in-addr.arpa name = dns.example.com.
Of cource my forticlient on windows in the same network works with the proxy to the server. And FireFox/wget on this Cent OS 7 server works with the proxy. Does anyone know anything about "Can not connect to proxy" error?

Answer 1

My IP was wrong and needed ip route add
Although the error message was "Can not connect to proxy", my destination forti IP was wrong. It was connected after I fixed it.
One more thing, I noticed a confusing point. I have two proxies like a socks proxy and a web proxy at this time. I knew ssl-vpn uses only web connections but I guessed forticlient might use ssh command during the connection. But it didn't. Forticlient_sslvpn needs only a web proxy so we just need to fill the proxy form of forticlient with a web proxy's url.
And one more thing. After I connected to ssl-vpn, it doesn't work perfectly because I can ping to internal server but not to DMZ(Of course my windows forticlient works well for both). I added ip route to DMZ and it started to work.
ip route add 192.168.3.0 via 10.0.0.5
I guessed this GW 10.0.0.5 is not the same everytime and every machine so I made the dynamic command.
ip route add 192.168.3.0/24 via $(ip route | grep 10.0.0 | awk '{print $3}' | head -1)
I hope this helps someone.