DSL and the Linux kernel

DSL and the Linux kernel

Post by bill » Sat, 28 Dec 2002 08:34:35



I'm trying to get the big picture on what's going on with the
Linux kernel in DSL.  As I understand it packets arrive to the
kernel "through the ppp0 interface"; the Linux kernel then forwards
these packets to the eth0 interface.  Is this correct?

Thanks,

bill

PS:  But what does it mean for an interface to deliver a packet to
the kernel?  I mean, the kernel is in a sense running the driver
that listens to whatever port DSL packets come in.

 
 
 

DSL and the Linux kernel

Post by David Efflan » Sat, 28 Dec 2002 11:40:58



> I'm trying to get the big picture on what's going on with the
> Linux kernel in DSL.  As I understand it packets arrive to the
> kernel "through the ppp0 interface"; the Linux kernel then forwards
> these packets to the eth0 interface.  Is this correct?

It delivers the ppp packets to wherever routing (and/or firewall) tells
the kernel they should go.  They would NOT normally go to the same
ethernet handling PPPoE.  If not destined the PPPoE box itself, there
would typically be another ethernet interface to deliver them to local
LAN.

Quote:> Thanks,

> bill

> PS:  But what does it mean for an interface to deliver a packet to
> the kernel?  I mean, the kernel is in a sense running the driver
> that listens to whatever port DSL packets come in.

Whether pppoe is handled by the kernel or an external program like
rp-pppoe, the kernel has to decide what to do with the packets once they
arrive (reject or drop, deliver locally, or forward to another IP).  It
may also have to alter packets (so outgoing traffic from private IPs
appear to be from its public IP).

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DSL and the Linux kernel

Post by bill » Sat, 28 Dec 2002 22:36:19


David, thanks for your reply.

Things are a bit clearer in my mind, but I would like to learn more
about all this.  Is there a book or article that explains in*
detail the relationship between the Linux kernel, packets, and
interfaces?

TIA,

bill

 
 
 

DSL and the Linux kernel

Post by David Efflan » Sun, 29 Dec 2002 13:11:37



> David, thanks for your reply.

> Things are a bit clearer in my mind, but I would like to learn more
> about all this.  Is there a book or article that explains in*
> detail the relationship between the Linux kernel, packets, and
> interfaces?

Look through the HOWTO files on your computer or goto http://www.veryComputer.com/

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