The Underscore Archives

Oliver Humpage wrote:
> We've got an ADSL backup line, and I've just got a small block of IPs from
> Plusnet (who really did have excellent customer service). What I want is to
> create a network where I can plug in a piece of kit, give it one of these
> public, routable IPs, and it's on the internet. I currently have a Dlink
> DSL-300T.
> 
> However, although this is possible with most ADSL modems for a *single* IP
> (i.e. just switch off the NAT), it seems that multiple IP addresses present
> a problem - the modem only thinks it's getting one WAN address, and that's
> all it's prepared to handle. I could just put the modem into "bridge" mode,
> but then any connected device has to use PPPoE to authenticate, which isn't
> fun. Is my understanding of that correct?

Funny you should mention this - we used to run our office off a DSL300T
and the problem is that DLink aim that product at the home market and
don't expect you do use it like that.

However, unless things have changed over the last couple of years, inside
it's a linux machine, so if you set an admin password you can telnet to
it and get a command line (note the 'admin' user is 'root' for telnet).

To give a specific example, we used to have 83.104.240.160/28 routed
to us and I'd configured the DSL300T to use 192.168.200.0/24 as the
internal NAT network with the router on 192.168.200.1 (which is what
you telnet to).  The DL300T insisted on something picking up the first
address (83.104.240.161 in this example) by DHCP but you could then
use the subsequent addresses directly, but you have to do the following
at the command line:

route add -net 83.104.240.160 netmask 255.255.255.240 dev br0
echo 1 > /proc/sys/net/ipv4/conf/br0/proxy_arp

I never figured out how to persuade the DLink to remember those over a
reboot :-(

We replaced it with a Cisco 857 last year so apologies if I've forgotten
anything in the recipe above.

HTH,

Andy


-- 
Andy Osborne - Technical Director
Conscious Solutions Ltd, University Gate East, Park Row, Bristol BS1 5UB
UK Co. Reg No. 4966976   VAT No. 826 2638 21
Tel: +44 117 903 1129  Fax: +44 117 903 9001  http://www.conscious.co.uk