From: Bakul Shah <bakul@bitblocks.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] bug or feature ? --- ip/ping -6
Date: Wed, 30 Dec 2015 16:16:34 -0800 [thread overview]
Message-ID: <20151231001634.A91CBB827@mail.bitblocks.com> (raw)
In-Reply-To: Your message of "Wed, 30 Dec 2015 23:36:22 GMT." <717ee4c69b676df9ba38b2297197add7@quintile.net>
On Wed, 30 Dec 2015 23:36:22 GMT "Steve Simon" <steve@quintile.net> wrote:
> > It is not a common factor if you ping broadcast.
>
> Yep, fair point.
If you're pinging plan9 machines, printing source address is
not useful as they sebd ping replies with source = broadcast
ip address. You have to look at the source ether addr to find
out which machine responded.
> I admit I have never done a ping broadcast.
>
> I did hear a story of somone who (in the early days of ethernet)
> built a ping broadcast packet, with the source address of the broadcast addre
> ss.
>
> This resulted in the mother of all packet storms.
>
> Maybe apocryphal, but a nice story none the less.
Seems apocryphal or must've been very early days! Ping
consists of sending an ICMP request packet, followed by the
responder(s) sending back ICMP reply packat(s). No ICMP
errors are sent in response to any ICMP message to avoid just
such a storm.
Ages ago you could send a *directed* broadcast to a place far
away, which would get routed to the right subnet and many or
all machines on that subnet would respond. Back then the 'Net
was a friendlier place and people didn't use NAT and script
kiddies were rather rare. All that changed a couple decades
ago.
next prev parent reply other threads:[~2015-12-31 0:16 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-28 9:04 arisawa
2015-12-29 0:10 ` Anthony Martin
2015-12-30 12:48 ` arisawa
2015-12-30 13:21 ` Charles Forsyth
2015-12-30 15:05 ` Steve Simon
2015-12-30 15:26 ` Kurt H Maier
2015-12-30 19:05 ` Steve Simon
2015-12-30 22:43 ` Kenny Lasse Hoff Levinsen
2015-12-30 23:36 ` Steve Simon
2015-12-31 0:16 ` Bakul Shah [this message]
2015-12-31 1:36 ` arisawa
2015-12-31 3:44 ` Dave Eckhardt
2016-01-02 1:12 ` erik quanstrom
2016-01-02 1:54 ` erik quanstrom
2016-01-03 19:58 ` hiro
2016-01-03 20:04 ` erik quanstrom
2016-01-03 20:31 ` erik quanstrom
2016-01-03 21:40 ` hiro
2016-01-03 21:43 ` hiro
2016-01-03 21:47 ` erik quanstrom
2016-01-04 1:31 ` erik quanstrom
2016-01-04 10:51 ` Anthony Martin
2016-01-04 13:04 ` erik quanstrom
2016-01-04 13:58 ` erik quanstrom
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20151231001634.A91CBB827@mail.bitblocks.com \
--to=bakul@bitblocks.com \
--cc=9fans@9fans.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).