On 2026-09-21 11:31:17 +0200, [email protected] wrote: > On Mon, Sep 21, 2026 at 10:51:58AM +0200, Vincent Lefevre wrote: > > On 2026-09-21 07:42:04 +0200, [email protected] wrote: > > > On Mon, Sep 21, 2026 at 02:50:09AM +0200, Vincent Lefevre wrote: > > > > On 2026-09-20 09:23:48 +0200, Marco Moock wrote: > > > > > Am 19.09.26 um 23:40 schrieb Vincent Lefevre: > > > > > > In any case, I don't see why IPv6 support in the kernel matters > > > > > > for nscd. I don't see any reason why nscd would do an IPv6 > > > > > > connection; that's useless for name resolving. > > > > > > > > > > nscd is only a cache for libc, it does not do any lookups. The sources > > > > > defined in nsswitch.conf do the lookups. > > > > > > > > This is incorrect: when nscd is running, nsswitch.conf is not > > > > used at all by the program that calls getaddrinfo! There's only > > > > a connection to "/var/run/nscd/socket". > > > > > > I think Marco meant that nscd itself looks into nsswitch (which > > > it does, at least the man page states it). Its clients (i.e. > > > the libc in the applications) consequently doesn't have to. > > > > Marco said "it does not do any lookups". If nscd looks into > > nsswitch.conf, then it will do the lookup. > > I think we are talking past each other: Marco's statement > (still in the quote above) is right "nscd is a cache" and > delegates the lookups to the sources in nsswitch (as libc > would do without nscd). Your statement "when nscd is running, > nsswitch is not used by the program" is /also/ right, but > they don't contradict each other -- because then it is > nscd who's using nsswitch on behalf of the program!
By "nscd" in my initial message, I meant the process in its entirety. What I meant is that IPv6 support in the kernel is useless for the nscd daemon, because name resolving on an IPv4-only network does not involve IPv6 connections. > > In any case, my remark is still: > > Why would nscd do any IPv6 connection? > > (i.e., why would nscd depend on IPv6 support in the kernel?) > > I think that is not the point. It is not the question which way > nscd gets at the DNS records (via IPv4 vs IPv6) but rather which > kind of records it gets (A vs AAAA). Or, more precisely, which > ones are preferred by the application. You are not answering the question: Why would nscd depend on IPv6 support in the kernel? I recall that the issue I got was a missing *IPv4* address[*] with nscd. I don't see why this would be a consequence of disabling IPv6 support in the kernel. [*] A missing IPv6 address could also occur, but I did not care for this machine. -- Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)
