[mdlug] Looking for IPv6 presenter for LUGWASH

[Jay Nugent]

Greets,

On Fri, 20 Jan 2012, Michael Mol wrote:

>>   I think you mean "static" IP address.
>
> No, I mean public IPv4 address. As in, publicly routeable. I'm on
> Comcast residential, so DHCP, but I have a publicly routable IPv4
> address (71.205.113.62, at the moment). It just changes every few
> weeks.

    Yes, exactly.  STATIC publicly routable, non-RFC1918 address.  A.k.a. 
'static'.  As opposed to a 'dynamic' publicly routable non-RFC1918 address 
that changes every few weeks.  I currently have TWO /25 blocks from my 
ISP (216.144.208/25 and 63.215.167/25).  I *can* live with a lot less 
so I am hoping to negotiate with the new ISP for a block of 32 addrs.

    And just because your address is served up via DHCP doesn't mean that 
it cannot be 'static' (never changing).  We did that all the time with 
each of the ISP's that I have done consulting work for (half dozen or so 
of them, so far).


> My understanding of ADSL is that non-primary* ADSL providers have
> their traffic routed through the primary's network on a tagged vlan,
> until it comes out at the ISP's POP. IIRC, I did find an ADSL provider
> in Seattle which could give me (in Grand Rapids) native IPv6, but my
> packets would be bouncing across the country.

    Coolness!


> * Don't know the exact term, sorry. Primary being the physical owner,
> non-primary being the ones who lease.

    In brief, for those on the list whom have ever wondered:

    The DSL signal is carried over the copper pair to the telephone Central 
Office where it is atteched to a specific physical port on a DSLAM.  The 
DSLAM *may* belong to the Telco, or it *may* belong to a provider.  But 
typically the Telco owns them and leases space.  ISP's subscribe to lease 
space on several DSLAMS in different Central Offices (CO) within a LATA or 
across a specific geographic region.  Some ISP's only support a small 
number of CO's, others lease DSLAM space across the entire state or 
country.

    The DSLAM is configured to pass your traffic using L2TP (layer 2 
Transport Layer) packets across an ATM (Asynchronous Transport) "cloud". 
THE DSLAM config states that your physical 'port' belongs to 'X' ISP, what 
the maximum allowed speed will be (1.5 down by 768k up), and routes the 
packets accordingly.  Each ISP (TelnetWW, Provide.net, DigitalRealm.com, 
WWnet, AT&T, etc.) subscribe to a connection off of this ATM cloud to 
collect the traffic from their subscribers.

    The L2TP packets come accross the ATM cloud into the ISP's 
"concentrator" (typically a large Cisco router) where the connection is 
then authenticated using RADIUS.  The RADIUS config tells the concentrator 
where these packets may flow (to private VPN, like AOL) or should they be 
allowed to reach the public Internet.  RADIUS also defines if the customer 
is 'dynamic' or 'static', and how large that static block of addresses is 
supposed to be.


    Well, that's it in a nutshell.  There are many more details involved, 
but this gives a general idea how the process works.

    Enjoy!
       --- Jay Nugent

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