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Re: [tlug] Slooooooow down: logs, smartctl, DNS?

On Sun, Jan 16, 2011 at 01:35, Dave M G <> wrote:
> I looked back on the thread and saw Jep suggest some kind of DNS
> problem. However, I thought DNS only applied to looking up web site
> addresses. How would that relate to my LAN?

Some people have dns setup on their local lan as well, to give names
to the hosts, for example. But even if you don't configure a dns
server manually your router most likely either runs one or acts as a
dns forwarder. Essentially giving your hosts a list of dns servers
they can use to query for website names, etc.... Your hosts most
likely pick up this information from the dhcp server your router
probably also provides. You can check out what your hosts have set as
their dns servers by looking in /etc/resolv.conf

> In any case, how would I go about diagnosing what is throttling the
> network connection?

I think starting tcpdump (sudo tcpdump -w capture.cap), doing one of
the things that you say is slow, then killing the tcpdump ^C
(control-C). Then open the tcpdump capture file in wireshark and take
a look at the traffic. Look for a lot of timeouts or retries. What
address is it retrying or timing out on? And take it from there.
That's what would be easiest for me anyway. But others may have other

> Thanks for any suggestions.
> --
> Dave M G
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Romeo Theriault

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