This is supposed to be a pretty simple question but I couldn't google a answer for it!
I have a ipsec VPN tunnel established between 126.96.36.199 and 188.8.131.52 (public IPs). The first machine (184.108.40.206) has a LAN with gateway 10.253.0.93. Inside this LAN, there is a machine with IP 172.21.83.60 (the gw already has the rules to forward traffic from 10.252.0.93 to 172.21.83.60).
In machine 220.127.116.11, I'm able to ping 10.252.0.93 normally. That's prove that the VPN is correctly established.
My question is: what I need to do in order to be able to ping machine 172.21.83.60 from 18.104.22.168? I tried to add a route using command:
route add -net 172.21.83.0 netmask 255.255.255.0 gw 10.253.0.93
SIOCADDRT: No such process