[AusNOG] another ipv6 Q

[Mark Andrews]

In message <A3FB5D9FD28C50429DF7692DC31054E606E47A67 at DC1INTADCW8201.yieldbroker.com>,
 Alex Samad - Yieldbroker writes:
> > 	2002:<ipv4>:: (6to4) is not recommended.
> 
> Care to explain why.
> 
> So you get a /48 without having to pay for it, you don't have to use it to =
> do  6to4.

If you are getting IPv4 address space from APNIC you can get IPv6
address space for $0.  You pay MAX(IPv4 cost, IPv6 cost).  ARIN and
RIPE have similar policies I believe.

> The only issue I see is if you can advertise the /48, but that would be a p=
> rocedural thing not a technical reason ... less there is something in the r=
> fc... but I am thinking that would be strange.

6to4 has lots of gotchas that regular IPv6 space does not have.

Firstly you do not advertise more specifics.  This is to prevent
having to import the entire IPv4 routing space into IPv6 thereby
effectively doubling the routing table.

You have idiots that filter IPv4 in IPv6.

You have firewalls that don't allow reply packets in.  They can come from
any IPv4 address not just the ones you send the encapsulated packets to.

You are depending apon the good will of others to {de}encapsulate
traffic.  Some of these boxes have been known to get overloaded.

> Alex
> 
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org