dilly
11-03-2006, 18:42
Got asked this and can't really answer as networking is not something i am familiar with. Can anyone help pls.
The following diagram shows the networking topology of a small office. The network will cater for 10 employees, allowing them to access certain services both internally and externally through a switch and the gateway node G. G is permanently connected to the Internet.
http://www.photobox.co.uk/album/album_photo.html?c_photo=50467982
Node S is a PC configured to act as an Internet server for the office’s domain name ee1160.com, and will have the following servers running on it:
• Domain name server
• Web server
• Mail servers (send and receive)
• File server (using FTP)
We wish to configure G in such a way that it allows only certain WAN-LAN (packets coming from the Internet to our LAN) traffic and blocks everything else based on port numbers.
Task
Draw up a chart as shown in the model answer, listing seven server applications to run on S and briefly describe what each application is used for and why you would allow/block its port for incoming traffic through G.
You can assume S is based on either Linux or Windows (not both) , but remember that S is the only server node to be accessed externally.
Model answer
The following table shows the required details for an imaginary file sharing server application.
Application - File Sharing (FSB)
Default Port No - 3903
Status Allow/block - block
Description - Used for peer-to-peer file sharing
Justification - Would allow unauthorised access to files on our PCs
The following diagram shows the networking topology of a small office. The network will cater for 10 employees, allowing them to access certain services both internally and externally through a switch and the gateway node G. G is permanently connected to the Internet.
http://www.photobox.co.uk/album/album_photo.html?c_photo=50467982
Node S is a PC configured to act as an Internet server for the office’s domain name ee1160.com, and will have the following servers running on it:
• Domain name server
• Web server
• Mail servers (send and receive)
• File server (using FTP)
We wish to configure G in such a way that it allows only certain WAN-LAN (packets coming from the Internet to our LAN) traffic and blocks everything else based on port numbers.
Task
Draw up a chart as shown in the model answer, listing seven server applications to run on S and briefly describe what each application is used for and why you would allow/block its port for incoming traffic through G.
You can assume S is based on either Linux or Windows (not both) , but remember that S is the only server node to be accessed externally.
Model answer
The following table shows the required details for an imaginary file sharing server application.
Application - File Sharing (FSB)
Default Port No - 3903
Status Allow/block - block
Description - Used for peer-to-peer file sharing
Justification - Would allow unauthorised access to files on our PCs