iptrace?

[Markus Schönhaber]

Dotan Cohen wrote:

> 2008/6/4 Markus Schönhaber <ubuntu-users at list-post.mks-mail.de>:

>> But is it reproducible in the sense that when it happens, it happens
>> more than once?
> 
> Yes, the problem could persist for 15 minutes, then browsing goes back
> to normal.

Good (in the sense that you can do some measurements when it happens again).
When it happens again, you could do the following:
- Close all network-related applications (browser, mail client etc.).
- Start tcpdump (you may have to install it):
sudo tcpdump -s 0 -w <some file name> -i <name of external interface>
- Do some webbrowsing.
We can take al look at what tcpdump captured afterwards.

> I don't think that they did. Actually, I'm almost certain that they
> did not. I will file a bug with Mozilla that such information should
> be included in the error message.

What I wanted to find out is whether it's really a firefox generated
message. In most error cases the server or the proxy will send an error
page which the browser simply displays but has no influence what info is
provided on this page - but the name of the server might be among them.

>> I'm not familiar with mtr. But two things catch my eye:
>> 1. The "Resolver error"s on some of the shots.
>> 2. The massive packet loss on some .bezequint.net machines.
> 
> That is the ISP's machine. They have seen the screenshots and say that
> is normal.

OK, in combination with what you mentioned in your other post, that this
was due to traffic shaping, this might be true. mtr sends ICMP echo
requests which might indeed get dropped in favour of more important
packets (but for very little gain).
Nevertheless this doesn't sound convincing to me. I'd rather read that
as: "Sorry, pal. When that happens to you, we have shaped you out of the
way. Bad luck, mate".

Since you started this thread with asking for iptrace which, as I
understand it, was suggested to you by your ISP's tech: it might be
worthwhile to find out, what exactly the tech wanted you to do with
iptrace, i. e. what exactly he wanted you to measure.
If you know that, you can probably do this measurement with some other
means/tool.

Regards
  mks