nanog mailing list archives
Re: IP addresses on subnet edge (/24)
From: Tom Hill <tom () ninjabadger net>
Date: Mon, 14 Sep 2020 23:19:10 +0100
On 14/09/2020 22:25, Andrey Khomyakov wrote:
TL;DR I suspect there are middle boxes that don't like IPs ending in .255. Anyone seen that?
Yes, but not for many, MANY years. I would expect that this service might not like addresses ending in .0 either? It was ca. 2010, when I started receiving an increasing number of complaints that connections from addresses ending in .0 or .255 were failing toward my (at the time) hosted services. This behaviour was eventually* narrowed to iptables rules carelessly included with 'Atomic Secured Linux' that purposely blackholed connections if the source address' most specific octet happened to contain .0 or .255. I'm sure that 'ASL' wasn't the only piece of software to have shipped with this default behaviour, so should you discover any box of any sort, configuration (or age) blindly hampering the connectivity for addresses with all-1s or all-0s in any of the three most-specific octets, please take this as infallible permission to promptly introduce it to the nearest body of water. :) * I still have AAISP - my home ISP at the time - to thank for routing me a /30 with a .255 address in it! It wouldn't have been as easy to resolve without that - very few UK consumers were being assigned addresses with .255 in them at the time. -- Tom
Current thread:
- IP addresses on subnet edge (/24) Andrey Khomyakov (Sep 14)
- Re: IP addresses on subnet edge (/24) Warren Kumari (Sep 14)
- Re: IP addresses on subnet edge (/24) Tom Hill (Sep 14)
- Re: IP addresses on subnet edge (/24) Töma Gavrichenkov (Sep 14)
- Re: IP addresses on subnet edge (/24) Jeremy Visser (Sep 15)
- Re: IP addresses on subnet edge (/24) Mark Andrews (Sep 14)
- Re: IP addresses on subnet edge (/24) Robert L Mathews (Sep 14)
- RE: IP addresses on subnet edge (/24) Brian Turnbow via NANOG (Sep 15)
- RE: IP addresses on subnet edge (/24) Joe Klein (Sep 15)