Re: Using /126 for IPv6 router links

[Tim Durack <tdurack () gmail com>]

On Mon, Jan 25, 2010 at 2:23 PM, Ryan Harden <hardenrm () uiuc edu> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Our numbering plan is this:
>
> 1) Autoconfigured hosts possible? /64
> 2) Autoconfigured hosts not-possible, we control both sides? /126
> 3) Autoconfigured hosts not-possible, we DON'T control both sides? /64
> 4) Loopback? /128
>
> Within our /48 we've carved it into (4) /50s.
> * First, Infrastructure. This makes ACLs cake.
> ** Within this /50 are smaller allocations for /126s and /128s and /64s.
> * Second, User Subnets (16k /64s available)
> ** All non-infrastructure subnets are assigned from this pool.
> * Third, Reserved.
> * Fourth, Reserved.
>
> We believe this plan gives us the most flexibility in the future. We
> made these choices based upon what works the best for us and our tools
> and not to conserve addresses. Using a single /64 ACL to permit/deny
> traffic to all ptp at the border was extremely attractive, etc.
>
> - --

This is what we have planned:

2620:0000:xx00::/41             AS-NETx-2620-0-xx00                             

        2620:0000:xx00::/44             Infrastructure                                  

                2620:0000:xx01::/48             Pop1 Infrastructure                     

                        2620:0000:xx01:0000::/64                Router Loopback (2^64 x /128)
                        2620:0000:xx01:0001::/64                Transit net (2^48 x /112)

                        2620:0000:xx01:0002::/64                Server Switch management
                        2620:0000:xx01:0003::/64                Access Switch management

                2620:0000:xx0f::/48             Pop16    Infrastructure         


        2620:0000:xx10::/44             Sparse Reservation                                      

        2620:0000:xx20::/44             Sparse Reservation                                      

        2620:0000:xx30::/44             Pop1 Services                                   

                2620:0000:xx30::/48             Cust1 Services

                        2620:0000:xx30:0001::/64                VLAN_1
                        2620:0000:xx30:4094::/64                VLAN_4094

                2620:0000:xx31::/48             Cust2 Services

                        2620:0000:xx31:0001::/64                VLAN_1
                        2620:0000:xx31:4094::/64                VLAN_4094

                2620:0000:xx32::/48             Cust3 Services

                        2620:0000:xx31:0001::/64                VLAN_1
                        2620:0000:xx31:4094::/64                VLAN_4094

                2620:0000:xx32::/48             Cust4 Services

                        2620:0000:xx31:0001::/64                VLAN_1

                        2620:0000:xx31:4094::/64                VLAN_4094

                2620:0000:xx32::/48     RES-PD-32       (4096 x /60)
                2620:0000:xx3f::/48     RES-PD-3f       (4096 x /60)

        2620:0000:xx40::/44             Pop2 Services                                   

        2620:0000:xx50::/44             Pop3 Services                                   

        2620:0000:xx60::/44             Pop4 services                                   

        2620:0000:xx70::/44             Pop5 Services                                   

This is a multiple campus network, customers are all internal. I have
had to squeeze Residential PDs down to /60s to make it fit. One Pop is
really 3 sites in one. This has had to be massaged into one Pop also.
To be safe, I'm thinking of adjusting loopbacks and ptp to be /64s.

I'm reasonably happy with the plan, but it doesn't seem to have that
much room to grow.

-- 
Tim:>
Sent from Brooklyn, NY, United States