Hello, On Sat, 30 Jul 2011 18:30:57 +0100 Brian Burch <br...@pingtoo.com> wrote:
> ... in other words, sshd no longer explicitly needs to listen on > either of the loopback interfaces - the generic "all IPv4 interfaces" > 0.0.0.0 is good enough. (As expected, other hosts could successfully > connect to sshd on the test system via its IPv4 interfaces because my > DNS resolves the hostname to only the IPv4 addresses). > I am satisfied the new version of ifupdown resolves my bug. However, > I would be interested in a brief explanation of why it works because > the source module is very hard for the uninitiated to read. The explanation is, when you connect to any of 127.1/8 addresses, you get back to the localhost, as per RFC 3330: A datagram sent by a higher level protocol to an address anywhere within this block should loop back inside the host. That works only if your dæmon listens on 0.0.0.0 or ::, and not explicitly 127.0.0.1. I have no explanation, however, why didn't it work before. At least, I couldn't reproduce it (yet). > In particular, I would like to try back-porting just the change for > my bug to the latest ubuntu source as a patch. I couldn't even > identify the relevant update from the changelog! Quite possible, that migration to iproute changed something, but I can't find anything important changed. -- WBR, Andrew
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