v6 & DSL / Cable modems [was: Private use of non-RFC1918 IP space
Mark_Andrews at isc.org
Wed Feb 4 21:45:38 CST 2009
In message <20090205030522.13D152B21F3 at mx5.roble.com>, Roger Marquis writes:
> Mark Andrews wrote:
> > All IPv6 address assignments are leases. Whether you get
> > the address from a RIR, LIR or ISP. The lease may not be
> > renewed when it next falls due. You may get assigned a
> > different set of addresses at that point. You should plan
> > accordingly.
> Exactly the problem, and the reason A) IPv6 is not and will not be a viable
> option any time soon (soon being before the publication of an IPv6 NAT
> RFC), and B) why network providers (and other parties who stand to gain
> financially) are firmly against IPv6 NAT.
> > If we could get a true accounting of the extra cost imposed
> > by NAT's I would say it would be in the trillions of dollars.
> This is exactly the sort of hyperbole, like RFC4864's proposing that
> application-layer proxies are a viable substitute for NAT, that discredits
> IPv6 proponents. Those who remember the financial industry's push for SET,
> a failed encryption technology, will be struck by the similarities in
> technical vs rhetorical arguments.
> Perhaps what we need is an IPv6 NAT FAQ? I'm suspect many junior network
> engineers will be interested in the rational behind statements like:
> * NAT disadvantage #1: it costs a lot of money to do NAT (compared to what
> it saves consumers, ILECs, or ISPs?)
> * NAT disadvantage #2 (re: your IPv6 address space) Owned by an ISP? It
> isn't much different than it is now. (say again?)
> * NAT disadvantage #3: RFC1918 was created because people were afraid of
> running out of addresses. (in 1992?)
> * NAT disadvantage #4: It requires more renumbering to join conflicting
> RFC1918 subnets than would IPv6 to change ISPs. (got stats?)
> * NAT disadvantage #5: it provides no real security. (even if it were true
> this could not, logically, be a disadvantage)
> OTOH, the claimed advantages of NAT do seem to hold water somewhat better:
> * NAT advantage #1: it protects consumers from vendor (network provider)
> * NAT advantage #2: it protects consumers from add-on fees for addresses
> space. (ISPs and ARIN, APNIC, ...)
Only until the consumers get wind of any rip-off pricing.
RIR's are charging ISP's about the same for a IPv6 /48 as
they do the a IPv4 address.
> * NAT advantage #3: it prevents upstreams from limiting consumers'
> internal address space. (will anyone need more than a /48, to be asked in
We already know some will need more than a /48. /48 was
only ever described as meeting the requirements of *most*
business and consumers.
> * NAT advantage #4: it requires new (and old) protocols to adhere to the
> ISO seven layer model.
Given were are running IP that is fiticious.
> * NAT advantage #5: it does not require replacement security measures to
> protect against netscans, portscans, broadcasts (particularly microsoft
> netbios), and other malicious inbound traffic.
What replacement? You just buy a IPv6 router with a firewall.
It will be about the same cost as a IPv4 router with a NAT.
> Roger Marquis
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: Mark_Andrews at isc.org
More information about the NANOG