Problem booting after Yum update of FC4

[James Wilkinson]

I suggested:
> Try "ping google.com" for several hours, and see how many packets you
> drop.
in response to a post implying intermittent network problems.

Tim objected:
> I hope you don't mean continuously.  That would constitute abuse.

I said:
> That's a fairly harsh definition of abuse you've got.

Mike McCarty wrote:
> It fits mine. It's not an attack, but it is an abuse.

OK. Two people have told me "it's abuse". So I should at least take the
objection seriously. You're telling me it's not a denial of service
attack (which is reasonable), or an attempt to harm Google. You're
telling me I'm suggesting using a service Google provides in a way that
is not reasonable.

I maintain that
 * it's necessary in the particular case to which I was responding (at
   least to do this to somewhere in the Internet)

 * Google are competent enough to understand that if they provide a ping
   service, people are likely to use it for the normal, expected
   purposes of that service.

 * Google are competent enough to know they're providing a ping service.

 * if someone provides a public service (e.g. a footpath), in the
   absence of any contrary signs or an attempt to keep the public out,
   there is an implied license to use that service in a reasonable
   manner.

Unfortunately, in order to diagnose certain sorts of network problems,
this sort of activity is necessary. Especially when you have
intermittent problems when only a few packets get dropped. Sometimes you
will get about 20% packet drops over a few minutes in a period of a
couple of hours.

Ping is the standard network tool for this sort of diagnosis, along with
traceroute. They're about *the* standard TCP/IP diagnostic tool, and
every version of ping I've seen has helpfully given you at the end
figures for how many and what proportion of packets were dropped. It's
reasonable that if people are interested in how many packets are
dropped, they'll run the tool and look at the output.

I maintain that from the original posting, implying transient and
intermittent network problems, something like this would have been
necessary for diagnosis (if only to rule out low-level network
problems).

I suppose I could have suggested his ISP's main web site instead.

> This guy sounds like "it doesn't matter that I broke into the
> car repair shop and used the tools there, because I put them
> all back when I was through with them."

I'm sorry, I don't think this analogy works. It implies I "broke
through" some sort of technical or signposted barrier.

A better one might be that someone provided a water fountain, and I
suggested one might fill a few water bottles from it, in the absence of
any signs to the contrary, and in such a way as not to deny the use of
the fountain to anyone else.

In this case, the question really becomes "how many is too much"?

> I suggest this: do you have a router? Try pinging that. I use
> a router between my DSL modem and my machine. It responds to
> pings. So does my DSL modem, for that matter.

I don't think you read the original post. It was reasonable to suspect
intermittent networking problems anywhere between the Original Poster
and the rest of the Internet, but not certain.

In particular, it was quite reasonable (and turned out to be the case)
that the problem was on the far side of the router. In which case,
pinging the router would not have shown much.

Sometimes, in troubleshooting, especially when each step has to be
reported back over e-mail to a list for further instructions, it helps
to test several things at once, and then drill down to see exactly which
one was at fault.

James.
-- 
E-mail address: james | "The duke had a mind that ticked like a clock and,
@westexe.demon.co.uk  | like a clock, it regularly went cuckoo."
                      |     -- Terry Pratchett, Wyrd Sisters