DSL Network Design Question

Sun Aug 14 12:07:22 UTC 2005

surfer at mauigateway.com wrote:
> I am going to be cutting over about 75,000 DSL lines from
> one core network to another.  Does anyone have
> recommendations on subnet and DHCP scope size?  If I make
> them /23s I have to do about 145 subents.  If I make them
> /22s I only have to do about 73.  Being mainly an always on
> eyeball network I don't see any problems with making big
> subnets (/22).  
> 
> 
> <flameproof undies == on>
> suggestions, recommendations, advice?
> 
> 
> scott
> 

Hi Scott,

I am connected through this beast:

  (1)  echnaton.lomiheim (192.168.48.228)  4.822 ms   5.726 ms   6.494 ms
   8   echnaton.serveftp.com (84.167.225.223)  88.974 ms   94.556 ms

           <DSL PPPoE>

  (2)  sepia (217.0.116.49)  75.121 ms   82.987 ms   93.851 ms
   7   sepia (217.0.67.101)  26.321 ms   24.930 ms   40.689 ms

  (3)  sepia (217.0.67.98)  97.179 ms   102.032 ms   110.439 ms
  (3)  sepia (217.0.67.102)  98.112 ms   105.508 ms   113.469 ms
  (3)  sepia (217.0.67.106)  92.877 ms   100.621 ms   108.924 ms
   6   da-ea1.DA.DE.net.DTAG.DE (62.153.179.54)  29.814 ms   28.022 ms   26.897 ms

  (4)  ams-e4.AMS.NL.net.DTAG.DE (62.154.15.2)  129.854 ms   137.460 ms   145.226 ms
   5   amx-gw2.nl.dtag.de (195.69.145.211)  30.964 ms   29.304 ms   27.540 ms
  (5)  gb-2-0-0.amsix1.tcams.nl.easynet.net (195.69.144.38)  153.946 ms   161.722 ms   169.569 ms

Numbers in (braces) are my traceroute out.
Numbers without are traceroute from outside in.

sepia (217.0.116.49) identifies as

Access-Concentrator: DARX41-erx
AC-Ethernet-Address: 00:90:1a:a0:01:46

I guess it is a Juniper ERX.

They used to give me an ip from one of four buckets each of them 16 buckets of
256 excluding xxx.xxx.xxx.0 and xxx.xxx.xxx.255

Since the end of last year it is only one bucket of 64k 84.167.xxx.xxx

Again I have never seen 0 or 255. I guess that means they have assigned some
256 routing groups. The whole block is /14 the groups are /24

They used to have 16k addresses but I guess that is close to their number of
dsl custmers in the Rhein/Main area, Frankfurt and Darmstadt. There were some
buckets that I have never seen assigned to me. I have seen them used statically.

Now they seem to have 64k addresses for an area with 250 000 inhabitants.
If Frankfurts count too then it is a million.

They try to clean up interrupting every session after 24 hours. But I guess
they still have a lot of customers who never go offline.

At the moment DTAG.DE is kind of a monopoly. Almost everybody has to use their
hardware for dsl.

Hope that helps you.

Regards,
Peter and Karin Dambier

-- 
Peter and Karin Dambier
Public-Root
Graeffstrasse 14
D-64646 Heppenheim
+49-6252-671788 (Telekom)
+49-179-108-3978 (O2 Genion)
+49-6252-750308 (VoIP: sipgate.de)
+1-360-448-1275 (VoIP: freeworldialup.com)
mail: peter at peter-dambier.de
http://iason.site.voila.fr
http://www.kokoom.com/iason