Laurent CARON wrote:
> Here is how it works on my DSL link.
> 
> I've got an interconnection IP which is used by the router itself, and a 
> netblock (/27) routed through the interconnection IP.

That's really cool.  You have a real routing subnet.

I have a block of IP addresses, that isn't a real subnet.  They're just 
IP addresses.  I could configure them as a subnet, but then I'd lose two 
of them, as I'd need a dummy "network address" and "broadcast address" 
in this case.

The Linux box receives one of these IP addresses, negotiated via PPP, 
when it sets up the PPPoE connection.  It appears as the ppp0 interface.

I also have some "bonus" IP addresses, that are neighbors of the main IP 
address for PPP.  I have aliases, ppp0:0, ppp0:1, and so on, to grab 
each of these IP addresses.  Linux can see packets coming into each of 
these IP addresses, and Shorewall is good about writing firewall rules 
to ensure they each get forwarded to the correct machine on the private 
side of my LAN.

The regular Ethernet interface, to the DSL modem, appears as the eth1 
interface.  It is up without an IP address, for use by ppp0.

I have an alias, eth1:0, which has an IP address, which is very good for 
being able to access the administrative page of the DSL modem while 
still remaining fully online.

If I had a real routing subnet, as I had several years ago, then my 
routing configuration would be greatly simplified!

Josh

> All my ip addresses are also passed through the same link (which is the 
> way it works).

I have two outgoing links.  One of them is DSL, over PPPoE, as described 
above.  The other is cable.  Cable is simpler, as it has a traditional 
Ethernet connection (not PPPoE), and gets its IP address via the usual DHCP.

> Can you say which model of DSL modem you do have ?

It's a Siemens SpeedStream 4100.

Josh

------------------------------------------------------------------------------
Come build with us! The BlackBerry® Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay 
ahead of the curve. Join us from November 9-12, 2009. Register now!
http://p.sf.net/sfu/devconf
_______________________________________________
Shorewall-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/shorewall-users

Reply via email to