20.01.2014 Views

Lectures notes for 2010 - KTH

Lectures notes for 2010 - KTH

Lectures notes for 2010 - KTH

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

Host vs. router - two behaviors<br />

• Hosts generate or sink IP packets<br />

• Routers <strong>for</strong>ward IP packets<br />

Thus it is possible <strong>for</strong> a device to be both a host and a router.<br />

Unless a host is explicitly configured as a router is not supposed to <strong>for</strong>ward IP<br />

datagrams. The default behavior must be never <strong>for</strong>ward.<br />

In linux the variable which controls this is: /proc/sys/net/ipv4/ip_<strong>for</strong>ward<br />

• If this variable is set to 1, then the node will per<strong>for</strong>m IP <strong>for</strong>warding.<br />

• If this variable is set to 0, then the node will not per<strong>for</strong>m IP <strong>for</strong>warding.<br />

Maguire Host vs. router - two behaviors 2: 13 of 52<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!