IS 3440 Discussion 6

As the Linux system administrator of insurance company Secure All, Inc., you need to design firewall rules for the organization’s bastion host file sever, which uses Samba. Located on the LAN the sever should allow Web application access for it’s online transaction platform to mount the filesystem, using a Linux computer as a gateway between a private network and the internet. Any internet connection whether it be a dial-up PPP, DSL, cable modem or a T1 line can be used. In the case of most dial-up PPP connections and cable modem connections, only a single IP address is issued allowing only one computer to connect to the internet at a time. Using Linux and iptables / ipchains one can configure a gateway which will allow all computers on a private network to connect to the internet via the gateway and one external IP address, using a technology called "Network Address Translation" (NAT) or masquerading and private subnets. Iptables/ipchains can also be configured so that the Linux computer acts as a firewall, providing protection to the internal network. Using NAT a bastion host should allow administrators to access Samba and SSH for remotely managing the server through NAT or PAT. These two filter methods will allow for a one way only gateway that is only accessed through certain ports or network addresses. Using this sort of port or network address filtering administrators can access the Samba server to perform administrative tasks, while the bastion host can only access the Samba server one way from it’s port or network