Here is another test when I connected to the VPN
C:\Users\rob>ipconfig
Windows IP Configuration
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Link-local IPv6 Address . . . . . : fe80::b045:e649:ce09:99c0%51
IPv4 Address. . . . . . . . . . . : 192.168.0.31
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . :
Ethernet adapter Local Area Connection:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Ethernet adapter TGB No Tunnel:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Ethernet adapter Ethernet:
Connection-specific DNS Suffix . : SSG5-Serial
Link-local IPv6 Address . . . . . : fe80::d507:9d76:dd42:bd34%7
IPv4 Address. . . . . . . . . . . : 192.168.177.60
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.177.1
Ping from the SRX
root@Gtown-VPN02% ping 192.168.0.31
PING 192.168.0.31 (192.168.0.31): 56 data bytes
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
^Z