::/0 (default gateway) or 2000::/3

[areguly]

why would the sample settings recommend setting:

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ip route add ::/0 dev he-ipv6

instead of

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ip route add 2000::/3 dev he-ipv6

?

what's the up side (or downside) ?

Thanks

[cholzhauer]

Because the first example you listed covers everything (once they assign something other than 2000::/3)

The 2000::/3 is only used on some linux kernels

[areguly]

that's what I don't understand... RFC4291 says Global ones are only 2000::/3, so what would I be missing?

you mean for when/if IANA decides that A000::/3 is also part of the Global pool?

[cholzhauer]

you mean for when/if IANA decides that A000::/3 is also part of the Global pool?

Exactly.  It's only a matter of time till they do that, and unless you change your default route, you won't be able to access places that use any range other than 2000::/3

BTW, did that RFC mention a reason they picked 2000::/3 instead of starting at the beginning?  Say 0001::/3?

[areguly]

they did not ...

here's more info from

http://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.txt

The IPv6 Unicast space encompasses the entire IPv6 address range with the exception of FF00::/8. [RFC4291] IANA unicast address assignments are currently limited to the IPv6 unicast address range of 2000::/3.

So you're right, at some point they may start assigning more blocks.

For convenience, here's the current status (as of 2010-10-29):

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   IPv6 Prefix      Allocation      Reference   
   0000::/8    Reserved by IETF     [RFC4291]
   0100::/8    Reserved by IETF     [RFC4291]
   0200::/7    Reserved by IETF     [RFC4048]
   0400::/6    Reserved by IETF     [RFC4291]
   0800::/5    Reserved by IETF     [RFC4291]
   1000::/4    Reserved by IETF     [RFC4291]
   2000::/3    Global Unicast       [RFC4291]
   4000::/3    Reserved by IETF     [RFC4291]
   6000::/3    Reserved by IETF     [RFC4291]
   8000::/3    Reserved by IETF     [RFC4291]
   A000::/3    Reserved by IETF     [RFC4291]
   C000::/3    Reserved by IETF     [RFC4291]
   E000::/4    Reserved by IETF     [RFC4291]
   F000::/5    Reserved by IETF     [RFC4291]
   F800::/6    Reserved by IETF     [RFC4291]
   FC00::/7    Unique Local Unicast [RFC4193]
   FE00::/9    Reserved by IETF     [RFC4291]
   FE80::/10   Link Local Unicast   [RFC4291]
   FEC0::/10   Reserved by IETF     [RFC3879]
   FF00::/8    Multicast            [RFC4291]



Thanks for the input, I guess for the time being I'll stick with routing only 2000::/3