On Friday 05 July 2019 08:27:50 Greg Wooledge wrote: > On Fri, Jul 05, 2019 at 06:15:02AM -0400, Gene Heskett wrote: > > 127.0.0.1 localhost > > 192.168.71.1 router.coyote.den router > > 192.168.71.3 coyote.coyote.den coyote > > 192.168.71.4 shop.coyote.den shop > > 192.168.71.5 lathe.coyote.den lathe > > 192.168.71.6 lappy.coyote.den lappy > > 192.168.71.7 sheldon.coyote.den sheldon > > 192.168.71.10 GO704.coyote.den GO704 > > 192.168.71.12 picnic.coyote.den picnc > > 192.168.71.21 MFC.coyote.den printer scanner > > 192.168.71.30 vna.coyote.den vna > > > > ::1 localhost ip6-localhost ip6-loopback > > > > ff02::1 ip6-allnodes > > ff02::2 ip6-allrouters > > > > #127.0.1.1 raspberrypi > > I don't know which machine this /etc/hosts is from, but see how the > last line is commented out, and has the name "raspberrypi", which > does not appear on any other line? > > If "raspberrypi" is supposed to be your machine's local hostname, then > you should uncomment that line. Or, if you prefer, add a line with > the machine's proper IPv4 LAN address plus its local hostname. > It is in fact picnc. picnc.coyote.den TBE.
> The purpose of having your local hostname in /etc/hosts (with *any* > valid address for it, even a loopback one like 127.0.1.1) is so that > processes which try to look up the local hostname before DNS is > working will get a valid response, and not freak out. > > Debian uses 127.0.1.1 for this by default, but encourages you to > override this with a static LAN address, if your host has one. If > you don't have a static LAN address, then the default will work. > > Since you commented out the default (again, assuming this machine's > local hostname is "raspberrypi"), any process that tries to look up > your hostname in the absence of DNS will throw a fit, and I wouldn't > care to predict the exact symptoms you'll see. Among them may be > processes dying immediately upon startup, processes hanging, processes > assuming things about your local network numbering scheme, processes > spewing error messages, and so on. > > sudo does a hostname lookup because, for some reason incomprehensible > to mortal women and men, it has a "host" field on every configuration > line. It seems that the intent is you'll write one gigantic-ass > sudoers file with lines for every host on your network all mixed > together, and drop a copy in /etc on every host; then, the "host" > field on each line will tell each machine which lines to ignore. > > I don't know *anyone* who does it that way, and the documentation does > not give any rationale for why sudoers has a "host" field, or what the > intended use of this field is... so that's just my guess. Its just as big a puzzle to me, but that rational does explain it. > So anyway, because of this "feature" that absolutely nobody uses, sudo > tries to look up your hostname, with multiple paths to failure if your > hostname is not properly defined. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>
