Re: Help diagnosing networking/internet performance issues
Re: Help diagnosing networking/internet performance issues
- Subject: Re: Help diagnosing networking/internet performance issues
- From: Conrad Shultz <email@hidden>
- Date: Mon, 22 Nov 2010 18:09:15 -0800
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 11/22/10 5:31 PM, Graham Cox wrote:
> In working on some networking code, I've come across one test machine
> on our local net that has extremely slow performance. Like orders of
> magnitude slower than normal, on the same local network and using the
> same method (airport, through a single router) as other machines that
> work just fine. This problem seems to affect not just the code I'm
> working on but general stuff like web browsing, file copying*, etc. A
> restart doesn't help, a full shutdown and reboot seems to help if the
> machine is left off for a while (overnight works, but 2 minutes has
> no effect) but the speed soon drops to a crawl after five minutes or
> so. Switching to wired ethernet makes no difference. It's very
> bizarre.
>
> Are there any diagnostic tools I can bring to bear to help figure out
> exactly where the problem is? It's probably a config file or
> something gone awry, but all the usual suspects (network settings,
> and so on) look fine.
Not exactly a Cocoa question, but since we've had a few questions
recently about how to intercept network stuff during Cocoa development,
the following comment I think might be of broader interest.
I would suggest you first analyze the traffic since you don't really
have any guesses as to what might be breaking.
Anything from DHCP confusion to bandwidth-consuming malware will be
revealed by a decent analyzer.
You can try using the built-in tcpdump, but Wireshark has a convenient
(if not entirely obvious) GUI.
(You probably did this already, but just in case it was overlooked, did
you disable wireless when testing wired? I must say the overnight vs.
two minute shutdown is suggestive of a hardware issue, perhaps requiring
some capacitors to discharge.)
My interest is piqued... please contact me off-list if you want to
discuss further.
- --
Conrad Shultz
Synthetiq Solutions
www.synthetiqsolutions.com
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (Darwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
iD8DBQFM6yJLaOlrz5+0JdURAj+wAJ0UlOxEtY6cDuEWhui8KhXqP8QvgwCggrg3
sPwNj4CNVZz9nhPR78eaC30=
=JULj
-----END PGP SIGNATURE-----
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden