[K12OSN] eth0 and eth1

Nils Breunese nils at breun.nl
Sun Sep 7 14:54:42 UTC 2008

Stephen Crampton wrote:

> Could someone please explain how an LTSP system decides how to use  
> eth0 and eth1?

The same as any Linux system: by using the route table.

> For instance, if I pull up firefox and type in cnn.com, over which  
> interface does my request go out?

That depends on your routing table. See the output of the 'route'  

> Which interface is serving DHCP and TFTP requests?

On K12LTSP it is eth0, I guess Edubuntu is simila.

> /etc/ltsp/dhcpd.conf doesn't seem to provide the answer.  The DHCP  
> script under /etc/init.d refers to a variable $INTERFACES, but I  
> cannot figure out where that variable is initialized.
> I'm assuming that, in the default case, firefox sends requests over  
> both interfaces, but dhcpd only uses eth0.  But how do I determine  
> whether this is true or not for my system?

Read up on TCP/IP routing. Individual applications (e.g. Firefox)  
don't decide this.

Nils Breunese.

More information about the K12OSN mailing list