IPv6 Address Planning

[Pim van Pelt]

Cody,
	
To add to the opinions, here's how BIT practices IPv6. We assign one /48 
to each core router in our network (and have room for 63 of those core 
routers currently:

2001:7b8::/32 BIT
2001:7b8:0000::/44 are points of presence (aka core-routers)
2001:7b8:0::/48 reserved
2001:7b8:1::/48 router1, 
2001:7b8:2::/48 router2, 
..
2001:7b8:3f::/48 router63

2001:7b8:40::/44 are transitnetworks (/64 each)
2001:7b8:40:1::/64 transitnet1
2001:7b8:40:1::/64 transitnet1
2001:7b8:80:: up to 2001:7b8:200:: are reserved in /44 chunks to
facilitate either new POP space or new transitnetworks.

2001:7b8:200::/40 customer allocations, 256 of size /48 each
2001:7b8:200::/48 customer0
2001:7b8:2ff::/48 customer255

2001:7b8:300::/40 is our SixXS tunnelbroker space, where
2001:7b8:300::/48 is /64 transitnetworks, and
2001:7b8:301::/48 sixxs-net1
2001:7b8:3ff::/48 sixxs-net255

2001:7b8:400::/40 and up are free for either tunnels or customers.

A POP consists of:
2001:7b8:3::/48 jun1.kelvin.network.bit.nl 
2001:7b8:3:XYYY::/64 where YYY are 12 bits for VLANs and X are 4 bits
for physical interfaces.

An exception to this rule is our DSL space. This done as follows:
2001:7b8:5:XXYY:ZZZZ::/80, where
XX is the ATM interface number, YY is the VCI and ZZZZ is the VPI. This
way we can number a lot of customers in one /48 while keeping a scalable
scheme. We do not autoconfigure our RFC1483 DSL downstreams, while we
have a pool (XX=255) which is planned to give out /80s to customers
using PPP autonegotiation.

I feel that using smaller-than /64 networks is just fine where one does
not need autonegotiation. Otherwise, ISPs will be throwing away large
amounts of /48s on DSL interconnects, allthough BIT might change this
policy later on in life [ie, when we have a tool which maps VCI/VPI to
/64 transitnetwork, and then numbering from 1 to N for customer links in
stead of deriving the transitnetwork from iface/vci/vpi directly].

Hope this helps.

-- 
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Pim van Pelt                 Email: pim at ipng.nl
http://www.ipng.nl/             IPv6 Deployment
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