nanog mailing list archives
Re: Smaller than a /24 for BGP?
From: Masataka Ohta <mohta () necom830 hpcl titech ac jp>
Date: Sun, 29 Jan 2023 16:06:12 +0900
William Herrin wrote:
The easiest way for applications know all the addresses of the destination is to use DNS. With DNS reverse, followed by forward, lookup, applications can get a list of all the addresses of the destination from an address of the destination.The DNS provides no such guarantee.
Guarantee for what? Remember that we have been enjoying secure confirmation that certain IP address belongs to certain hostname by DNS reverse look up without any guarantee. > Moreover, the DNS does guarantee > its information to be correct until the TTL expires, making it > unsuitable for communicating address information which may change > sooner. I'm afraid you know very little about DNS operation. See rfc1034: If a change can be anticipated, the TTL can be reduced prior to the change to minimize inconsistency during the change, and then increased back to its former value following the change. which is the way to operate DNS when host addresses are changing, for example, by multihoming configuration changes. In addition, when a dual homed site with end to end multihoming changes one of its ISP, it is a good idea to offer all the three addresses by DNS during the change. Make before break.
With TCP, applications must be able to pass multiple addresses to transport layer (e.g. BSD socket). which implies addresses are supplied from applications by DNS look up.Which is a bit of hand-waving since the protocol can't do anything with that information regardless of whether you expand the API to provide it.
Read my draft, which explains how TCP should be modified. Masataka Ohta
Current thread:
- Re: Smaller than a /24 for BGP?, (continued)
- Re: Smaller than a /24 for BGP? John Levine (Jan 24)
- Re: Smaller than a /24 for BGP? Forrest Christian (List Account) (Jan 24)
- Re: Smaller than a /24 for BGP? Lars Prehn (Jan 25)
- Re: Smaller than a /24 for BGP? Masataka Ohta (Jan 27)
- Re: Smaller than a /24 for BGP? William Herrin (Jan 28)
- Re: Smaller than a /24 for BGP? Donald Eastlake (Jan 28)
- Re: Smaller than a /24 for BGP? William Herrin (Jan 28)
- Re: Smaller than a /24 for BGP? William Herrin (Jan 28)
- Re: Smaller than a /24 for BGP? Masataka Ohta (Jan 28)
- Re: Smaller than a /24 for BGP? William Herrin (Jan 28)
- Re: Smaller than a /24 for BGP? Masataka Ohta (Jan 28)
- Re: Smaller than a /24 for BGP? William Herrin (Jan 29)
- Re: Smaller than a /24 for BGP? John Levine (Jan 24)
- Re: Smaller than a /24 for BGP? Masataka Ohta (Jan 28)
- Re: Smaller than a /24 for BGP? Masataka Ohta (Jan 29)
- ROV concern for hyper-specific prefixes (renamed from `Re: Smaller than a /24 for BGP?') Amir Herzberg (Jan 30)
- Re: ROV concern for hyper-specific prefixes (renamed from `Re: Smaller than a /24 for BGP?') Tom Beecher (Jan 30)
- Re: ROV concern for hyper-specific prefixes (renamed from `Re: Smaller than a /24 for BGP?') Amir Herzberg (Jan 30)
- Re: Smaller than a /24 for BGP? Eric Kuhnke (Jan 25)
- Re: Smaller than a /24 for BGP? Jon Lewis (Jan 25)
- Re: Smaller than a /24 for BGP? Mike Hammett (Jan 26)