[clue-tech] DHCP Server and Package Install Date

[David L. Willson]

On Sun, 10 Aug 2008 22:27:33 -0600, David L. Anselmi wrote
> David L. Willson wrote:
> > How do I determine which DHCP server leased my address to me, without looking at
> > anything but my own machine?  Earlier, I had a machine that had a bad address, but I
> > blamed the wrong host for issuing the bad address.  I could have saved some time by
> > knowing which host issued the address.
> 
> You shouldn't have multiple DHCP servers on the same subnet, the 
> protocol doesn't allow it (where are they at with failover, anyway?) 
> There's something to be said for paying attention to what you've done 
> and what you're doing.

Dave.  I know not to have two DHCP server on the same subnet.  The machine that gave the
bad address was a rogue, but I didn't know ~which~ machine had brought up the rogue DHCP
server...

> You can run multiple servers on multiple subnets on the same LAN segment 
> but you have to be pretty careful.  And even without DHCP that's the 
> road to madness so don't do it.  (Unless you're a big time VLAN guy, 
> maybe they get used to doing that.)
> 
> As Peter said the DHCP server gets logged when the lease is granted (and 
> ipconfig shows it right to you on Windows).  If you have machines 
> sharing IP addresses, that's bad too.  Then you have to differentiate by 
> MAC but your arp table only shows the latest entry.

Yeah, Peter's answer was better than yours.  No cookie for you.  "Road to madness" indeed...

> > How do I find out the order or times of package installations on my machine?  All
> > weekend, I've been using imapsync, which has an unstated dependency on
> > libdate-manip-perl.
> 
> You're kidding, right?  Life is too short to deal with "unstated 
> dependencies".  Use something that isn't junk.

And your preferred IMAP mailbox synchronizing tool is?  imapsync's not junk, it just has
that one tiny disabling flaw.  :-)

> I should get a blog.  Then I could put a rant up about how important it 
> is to keep track of how things work when other people have to use your 
> stuff.  Einstein didn't have to remember his phone number because it was 
> easy to look up.  But that's only because someone bothered to write it 
> down for him.  (I have a feeling about how dependency management makes 
> or breaks distros, but that goes on the blog.)
> 
> > I wanted to transfer the job to another machine, but I couldn't
> > remember the unstated dependency.  I could have saved time and a failed run of imapsync,
> > by just asking my system, "What did I install right after I installed imapsync?" but I
> > couldn't figure out how to ask that.
> 
> aptitude and dpkg keep logs of what they do.  Of course logs tend to get 
> rotated out but I seem to have dpkg logs almost a year old.

In /var/log/apt, and I sudo grep -A10 imapsync /var/log/apt/term.log, and BINGO, there's
libdate-manip-perl, 16 minutes after imapsync!  Good answer, Dave.

> > Ok geeks, ring in when ready.
> > 
> > Dave, I'm sorry, I'm burning two questions that would have been good ones for the "geek
> > tournament".
> 
> If you try to grade this I won't answer any more questions. :-)

I'll see ~that~ when I believe it.