Thank you Gustaf Neumann. Your reply was really helpful and based on it, I redesigned my net configuration for failsafe working using Pound & Squid which is given below.
Public IPs ( Gateways from three different ISPs)
1) 63.34.54.67
2) 56.34.67.23
3) 62.45.67.34
I configure Squid on each gateway server as Proxy.
SERVER1: NIC1 - 63.34.54.67, NIC2 - 192.168.0.10, Squid listen on 192.168.0.10:8080 and use public IP 63.34.54.67.
SERVER2: NIC1 - 56.34.67.23, NIC2 - 192.168.0.20, Squid listen on 192.168.0.20:8080 and use public IP 56.34.67.23.
SERVER3: NIC1 - 62.45.67.34, NIC2 - 192.168.0.30, Squid listen on 192.168.0.30:8080 and use public IP 62.45.67.34.
Now, I configure Pound on SERVER4, IP 192.168.0.40, and all clients connect to that IP 192.168.0.40.
ListenHTTP
Address 192.168.0.40
Port 80
Service
BackEnd
Address 192.168.0.10
Port 8080
End
End
Service
BackEnd
Address 192.168.0.20
Port 8080
End
End
Service
BackEnd
Address 192.168.0.30
Port 8080
End
End
End
Do you think it is workable configuration? Will it keep all connections from clients to internet, including ssl & RDP sections, alive even if the Gateway through which it is connected currently fails? Please help.