In message <50F70524.4020102@fredan.se>, fredrik danerklint writes:
Even tough you have very good arguments, my suggestion would be to have a class A network (I got that right, right?) for all the users and only havi ng 6rd as service on that network.
ARIN and IETF cooperated last year to allocate 100.64.0.0/10 for CGN use. See RFC 6598. This makes it possible to implement a CGN while conflicting with neither the user's RFC1918 activity nor the general Internet's use of assigned addresses. Hijacking a /8 somewhere instead is probably not a great move.
Ok.
If I have calculated the netmasks right that would mean to set aside:
2001:0DB8:6440::/42
for the use of 6rd service:
2001:0DB8:6440:0000::/64 = 100.64.0.0 .... 2001:0DB8:647F:FFFF::/64 = 100.127.255.255
No. With 6rd you DROP the top 10 bits and you give every customer a /56. And you can repeat the exercise 4 times within a /32. /etc/dhcpd.conf: subnet 100.64.0.0 netmask 255.240.0.0 { range 100.64.0.2 100.64.255.254; router 100.64.0.1; option 6rd 10 34 2001:DB8:: 2001:DB8::1; } subnet 100.64.0.0 netmask 255.240.0.0 { range 100.64.0.2 100.64.255.254; router 100.64.0.1; option 6rd 10 34 2001:DB8:4000: 2001:DB8:4000:1; } subnet 100.64.0.0 netmask 255.240.0.0 { range 100.64.0.2 100.64.255.254; router 100.64.0.1; option 6rd 10 34 2001:DB8:8000: 2001:DB8:8000:1; } subnet 100.64.0.0 netmask 255.240.0.0 { range 100.64.0.2 100.64.255.254; router 100.64.0.1; option 6rd 10 34 2001:DB8:c000: 2001:DB8:C000:1; } -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: marka@isc.org