nanog mailing list archives
Re: WKBI #586, Redploying most of 127/8 as unicast public
From: "John Levine" <johnl () iecc com>
Date: 17 Nov 2021 22:03:03 -0500
It appears that Joe Maimon <jmaimon () jmaimon com> said:
Mark Andrews wrote:It’s a denial of service attack on the IETF process to keep bringing up drafts like this that are never going to be approved. 127/8 isin use. It isn’t free. There are so many things wrong with this statement that I am not even going to try to enumerate them.
Aw, c'mon, don't leave us guessing.
For example https://datatracker.ietf.org/doc/html/draft-fuller-240space-02 from 2008 which fell prey to the "by the time this is usable IPv6 will have taken over" groupthink. Objectively wrong.
I will agree that your explanation of the reasons the IETF didn't repurpose 240/8 is objectively wrong. The amount of work to change every computer in the world running TCP/IP and every IP application to treat 240/4 as unicast (or to treat some of 127/8) is not significantly less than the work to get them to support IPv6. So it would roughly double the work, for a 2% increase in the address space, or for 127/8 less than 1%. The code for IPv6 is already written, after all. Also, while the world has run out of free IPv4 address space, there is plenty of IPv4 if you are willing to pay for it. A 2% increase in v4 addresses would not change that.
"By contrast, IPv6, despite its vastly larger pool of available address space, allocates only a single local loopback address (::1)[RFC4291]. This appears to be an architectural vote of confidence in the idea that Internet protocols ultimately do not require millions of distinct loopback addresses.”This is an apples-to-oranges comparison. IPv6 has both link and site local addresses and an architecture to deliver packets to specificinstances of each. This does not exist in the IPv4 world. SO an IPv6 only system without any network interfaces can run multiple discrete instances of the same daemon accepting connections on the same TCP port?
Sure. Can I script that, can I template that with hardcoded
addresses, same as I can now for 127/8?
Sure, if you think that's a good idea which it isn't. Use LLAs on your loopback interface. Personally, I take my 127/8 addresses from a configuration file since I don't know in advance what other daemons might also want to run on addresses only visible on the local machine. Or, you know, some maniac might decide that part of 127/8 isn't loopback so I have to move them to the part that still is. In IPv6 I use ULAs since that gives me the option of routing them or not. R's, John
Current thread:
- Redploying most of 127/8 as unicast public Jay R. Ashworth (Nov 17)
- Re: Redploying most of 127/8 as unicast public scott (Nov 17)
- Re: Redploying most of 127/8 as unicast public Mark Andrews (Nov 17)
- Re: Redploying most of 127/8 as unicast public Joe Maimon (Nov 17)
- Re: WKBI #586, Redploying most of 127/8 as unicast public John Levine (Nov 17)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Joe Maimon (Nov 17)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Mark Andrews (Nov 17)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Joe Maimon (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public John R. Levine (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Joe Maimon (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Justin Streiner (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public David Conrad (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Jim (Nov 18)
- Re: Redploying most of 127/8 as unicast public Mark Andrews (Nov 17)
- Re: Redploying most of 127/8 as unicast public scott (Nov 17)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Nick Hilliard (Nov 18)
- Re: WKBI #586, Redploying most of 127/8 as unicast public Steven Bakker (Nov 18)