| Linux
Masquerading Router Client: Default Gateway: The IP address of the interface on the linux box that is presented to the local network, typically 192.168.0.1 DNS - Enable DNS!!! Enter a host name for the computer (it can be anything) and put in 2 DNS servers supplied by your provider. You MUST enter DNS server information even if the provider ordinarily supplies this information on connection, because as far as the clients are concerned, it looks like an ordinary LAN, and this is how an ordinary LAN works. Generally this information is stored in the /etc/ppp configuration files of the linux host while the connection is active. If you don't know and can't find out the DNS server information, you can use any 2 valid servers from anybody. The worst that could happen is that the masquerading router would seek out one set of servers to resolve DNS names while the clients would use another, but they will both work. Host: Local interface IP address must match the address you put in all the client software, typically 192.168.0.1. The rest of the settings are determined either by the provider or the software used to establish the outside connection. |
| Proxy Servers Client: Default Gateway: <NONE needed>. As far as the client is concerned the Proxy is the real thing. Internet browser: Manual Proxy configuration. Set the IP address of the Proxy server to match its local IP. Set the port numbers for the services (HTTP, SMTP, POP, FTP, etc) according to the proxy server's instructions Mail clients: Consult product documentation. Typically the setup is to set the proxy as the SMTP and POP server for the clients and enter the real names of the servers assigned by the ISPs in the host's configuration files. Host: Local interface IP address decided by you, to match the address you put in all the client software, typically 192.168.0.1 As per above, you may have to enter the SMTP and POP servers that the clients are using (consult documentation for the Proxy Server) Default Gateway Remote interface -- IP address, gateway and subnet mask are assigned by the service provider (left blank if dynamic) |
| Routers (whether home-made or commercial) are set up
as follows: Client: Default Gateway: Router address, typically 192.168.0.1 Internet browser: Direct connection to the Internet Mail clients: as assigned by the ISP unless you have such services as Sendmail, Postfix, etc installed on your local machine or on the router and wish to use them. Host: Local interface IP address matches Gateway address for the clients, typically 192.168.0.1 Default Gateway <NONE> (this machine IS the gateway!) Remote interface -- IP address, gateway and subnet mask are assigned by the service provider (left blank if dynamic) |
| Configuring Services on the Clients The biggest headache is generally FTP. For a masquerading router, the solution is to either 1.) use passive ftp (configure the client to use this mode) or to 2.) install the ftp_masq module (more complicated) Real Audio transport is blocked by some proxy servers, but this can be overridden in the Real Audio software by configuring it to "Use HTTP Transport Only", and with Proxy Servers, set the Proxy Server address and port number as well. Providers of services, such as Instant Messaging, are updating their software to allow it to work with firewalls.either of these schemes. I've personally used Yahoo Instant Messenger behind an IP-masquerading router. |