at&t business ipv6

Thu Jun 21 16:19:43 UTC 2018

> Yes, one particular plotline which can explain why docsis systems do
> this is that standard residential customers are provisioned using
> giant broadcast domains directly on the cable, with DHCP config.
> Obviously it's more complicated because it's docsis, but lemme
> handwave and say that this is the gist of it.  Because you're dealing
> with giant broadcast domains, you assign IP address blocks to
> individual CMTSs and your customers are assigned out of those ranges.
> 
> Assigning ipv6 in this context is really simple: it's part of the
> baseline DOCSIS3.0 standard and is supported incredibly well by all
> parts of the network.
> 
> Static addresses don't fit into this paradigm because you if you
> configure your static customers from a single broadcast domain, then
> they are glued to a particular CMTS and can't be moved from that CMTS
> unless you renumber them.
> 
> This doesn't work in practice because if you want to grow your
> network, you probably want to be able to move around chunks of your
> cable network from one CMTS to another in order to balance out your
> traffic.  Or you might want to split a bunch of cable nodes from one
> CMTS to multiple, according as your traffic outgrew the capabilities
> of a single CMTS (a node in this context is a small chunk of a cable
> network).
> 
> One way of getting around this mess is to backhaul all your static
> customer interfaces using mpls l2vpn PWHE up to a L3 box which just
> handles static IP addresses.  You configure the customer's static
> default gateway IP address on an interface on this head-end router,
> and the customer's cable modem will have a virtual connection directly
> to that interface.  The thing is, this virtual interface termination
> system might or might not be tied into the entire ipv6 provisioning
> system.  If it isn't, you're SoL.  So even if dirt-cheap residential
> customers can get ipv6 very easily, it's different by virtue of the
> fact that you're using static IP addresses, because they're a headache
> for cable operators.

aha!  makes sense.

i'll settle for dynamic.  if i need static internally, i can always do
nat66 :)/2

i do not want to play how hard can we make ipv6 deployment; just want to
enable it on a five-segment office lan.

but i am beginning to see that there may be a reason i am having
problems getting past an account rep.

randy