nanog mailing list archives
Re: IPv6 news
From: Tony Li <tony.li () tony li>
Date: Sun, 16 Oct 2005 01:45:40 -0700
Doesn't NAT, or more specifically the most commonly used, NAPT, create hard state within the network, which then makes it violate the end-to-end argument ? Also, because it has to understand transport andapplication layer protocols, to be able to translate embedded addresses,doesn't this also make it violate end-to-end ? I've understood thefundamental benefit of following the end-to-end argument is that you endup with a application agnostic network, which therefore doesn't create future constraints on which applications can then be used over that network. In an end-to-end "compliant" network, any new transport layerprotocols, such as SCTP or DCCP, and new user applications, only requirean upgrade of the end or edge node software, which can be performed in an incremental, per edge node as needed basis. In other words, there isn't any whole of network upgrade cost or functionality deploymentdelay to support new applications, which was the drawback of applicationspecific networks, such as the traditional POTS network. Have I somehow misunderstood the intent or benefits of the end-to-end argument ?
Mark,This is probably the most common misunderstanding of the end-to-end principle out there. Someone else can dig up the quote, but basically, the principle says that the network should not replicate functionality that the hosts already have to perform. You have to look at X.25's hop-by-hop data windows to truly grok this point.
Many people pick this up and twist it into ~the network has to be application agnostic~ and then use this against NATs or firewalls, which is simply a misuse of the principle. Really, this is a separate principle in and of its own right. It's not one that I subscribe to, but that's a different conversation...
Regards, Tony
Current thread:
- Re: IPv6 news, (continued)
- Re: IPv6 news John Payne (Oct 14)
- Re: IPv6 news Tony Li (Oct 15)
- Re: IPv6 news Joe Abley (Oct 15)
- Re: IPv6 news John Payne (Oct 15)
- Re: IPv6 news Tony Li (Oct 15)
- Re: IPv6 news David Conrad (Oct 15)
- Re: IPv6 news Paul Vixie (Oct 15)
- Re: IPv6 news David Conrad (Oct 15)
- Re: IPv6 news Tony Li (Oct 15)
- Re: IPv6 news Mark Smith (Oct 16)
- Re: IPv6 news Tony Li (Oct 16)
- Re: IPv6 news Michael . Dillon (Oct 17)
- Re: IPv6 news David Meyer (Oct 17)
- Re: IPv6 news Mark Smith (Oct 17)
- And Now for Something Completely Different (was Re: IPv6 news) David Conrad (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Mark Smith (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Tony Li (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Randy Bush (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Tony Li (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Joe Maimon (Oct 16)
- Re: And Now for Something Completely Different (was Re: IPv6 news) Tony Li (Oct 16)