20.01.2014 Views

Lectures notes for 2010 - KTH

Lectures notes for 2010 - KTH

Lectures notes for 2010 - KTH

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Linux firewall<br />

For example, <strong>for</strong> the software firewall used in Linux systems called “ipfwadm”:<br />

• all ports are typically closed <strong>for</strong> inbound traffic,<br />

• all outbound traffic is “IP masqueraded”, i.e., appears to come from the<br />

gateway machine; and<br />

• For bi-directional services required by the users, “holes” may be<br />

punched through the firewall - these holes can reroute traffic to/from<br />

particular ports:<br />

• to specific users or<br />

• the most recent workstation to request a service.<br />

Maguire Linux firewall 12: 13 of 30<br />

maguire@kth.se <strong>2010</strong>.03.21 Internetworking/Internetteknik

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!