DHCPv6 PD chains vs bridging

Charles Wyble charles at thewybles.com
Tue May 5 15:57:38 CDT 2009

David W. Hankins wrote:
> On Tue, May 05, 2009 at 04:22:04PM -0400, Paul Timmins wrote:
>> Sorry for the top post, but as a crazy thought here, why not throw out an 
>> RA, and if answered, go into transparent bridge mode? Let the sophisticated 
>> users who want routed behavior override it manually.
> Customer premise gear has a 'front side' and a 'back side',

I presume by front you mean wan and back you mean lan?

  and it is
> already well ingrained behaviour for 'back-to-back port chaining' to
> create a single large bridged network in the home. 

Really? What CPE?

My topology at home is

motorolla dsl modem[1]->cisco 1841->catalyst 2924->wireless router->clients

The connection between the modem and router is a routed connection. The 
default configuration of the Linksys kit I have seen is routed. I had to 
change it to operate as a bridge (a one click option in the gui), and 
turn off the local DHCP server to make a flat wired/wireless network.

Otherwise it insists on being a router.

(It would appear that SBC recently changed their network to only allow 
their CPE with it's very limited configuration options. It's routed. 
Public IP on the WAN  and a fixed private IP ( It hands 
out 1 private DHCP address (

  What is the
> customer's anticipated result from front-to-back chaining?

I'm not sure how many people do this. Many people have one integrated 
device hanging off their DSL modem. They then purchase wireless 
extenders to increase the reach. This is what I overhear being recommend 
by Frys and BestBuy sales folks, and it seems to work well.

I don't know how many will do it in the future. I imagine that vendors 
will just make beefer wireless routers to handle increased load. They 
already have different models and software feature sets for "high end 

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