Something

rede_ubatuba: 192.168.4.0/24
rede_SP: 192.1.1.0/24

vpn_ubatuba --> internet --> vpn_sao_paulo

(entre elas tudo ok, eu pingo normalmente)

                             IP2        IP1
vpn_ubatuba --> internet --> vpn_sao_paulo -----------> maquina_interna
                             (rota interna no OpVPN)    (rota para ubatuba apontando para IP1)
                             (forward habilitado)

(A conexao nao volta para VPN_Ubatuba)

rotas da "maquina_interna¨ 
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.1.1.0       0.0.0.0         255.255.255.0   U     0      0        0 eth0
201.20.200.0    0.0.0.0         255.255.248.0   U     0      0        0 eth1
192.168.0.0     192.1.1.30      255.255.0.0     UG    0      0        0 eth0
0.0.0.0         201.20.200.1    0.0.0.0         UG    0      0        0 eth1


===========

Rotas vpn_sao_paulo
vpn:/etc/init.d# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.1.1.4        0.0.0.0         255.255.255.255 UH    0      0        0 tun1
192.168.4.0     10.1.1.3        255.255.255.0   UG    0      0        0 tun1