Frustrated that I don't UNDERSTAND why my network times out - Page 4

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Re: Frustrated that I don't UNDERSTAND why my network times out
it times out - done -

http://mxtoolbox.com/SuperTool.aspx?action=http%3acentos.org&run=networktools#




Re: Frustrated that I don't UNDERSTAND why my network times out
ps56k wrote:
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Presently centos.org is down for everyone

http://www.downforeveryoneorjustme.com/centos.org It's not just you!  
http://centos.org looks down from here.

http://www.isup.me/www.centos.org It's not just you!  
http://www.centos.org looks down from here.


That has not been the case for the duration of this thread.




--  
Mike Easter

Re: Frustrated that I don't UNDERSTAND why my network times out
Mike Easter wrote:

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Initiating server query ...
Looking up IP address for domain: www.centos.org
The IP address for the domain is: 85.12.30.227
Connecting to the server on standard HTTP port: 80
The port is closed, so our connection attempt was refused.
Query complete.

--  
Mike Easter

Re: Frustrated that I don't UNDERSTAND why my network times out
weird - yup -
it times out from my network - and other "online testing sites" -
so... ????

Ping -          centos.org - 85.12.30.227       --> Amsterdam location
Ping - www.centos.org - 72.232.194.162 ---> ????

So, where does the -    72.232.194.162      come from ??
vs my DNS lookup is showing 85.12.30.227   ??

  2  NS1.LAYEREDTECH.COM  72.232.1.236
AUTH  0 ms  Received 1 Answers , rcode=
PTR: PointerName=www.centos.org,

cname:www.centos.org
Lookup failed after 1 name server timed out or responded non-authoritatively

-----------
Here's his traceroute run:
knoppix@Microknoppix:~$ traceroute www.centos.org
traceroute to www.centos.org (72.232.194.162), 30 hops max, 60 byte

----------
      HopCount IP Address HostName
      1 208.123.79.34 net208-123-79-34.static-customer.corenap.com
      2 198.252.182.180 aus-core-10-v12.corenap.com
      3 24.155.184.106 xe-0-0-2-509.AUSTTXMIM002.aggr09.austtx.grandecom.net
      4 24.155.121.76 xe-0-0-0-0.aggr08.austtx.grandecom.net
      5 4.30.74.53 ae5-868.edge9.Dallas1.Level3.net
      6 4.69.145.200 ae-4-90.edge3.Dallas1.Level3.net
      7 4.71.170.6 LAYERED-TEC.edge3.Dallas1.Level3.net
      8 * * * * * *
      9 72.232.194.162 www.centos.org


---------

their TCP/IP world seems messed up somewhere within their DNS records -



Re: Frustrated that I don't UNDERSTAND why my network times out
ps56k wrote:
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That is the correct IP.

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That is not the correct IP resolution according to google's DNS.

That is, www.centos.org resolves to 85.12.30.227 but 85.12.30.227 does  
not rDNS to www.centos.org

However, 72.232.194.162 rDNS to www.centos.org which does not resolve to  
72.232.194.162

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The DNSreport on centos.org says the MX, SOA, WWW, are all OK but the  
Parent nameservice fails on one dns report but not another.

Parent    Failed    Parent nameservers centos.org    Your NS records at the  
parent server are:

Failed    Nameservers for domain in DNS centos.org    Your NS records at your  
nameservers are:

However, my dig worked OK showing ns1, ns3, & ns4.centos.org and their  
IPs and all 3 nameservers produced the MXes etc.

The report at mxtoolbox said the ns at the parent was OK, but then the  
information said it was not.  I don't understand this inconsistency in  
the parent DNS status for centos.org.



--  
Mike Easter

Re: Frustrated that I don't UNDERSTAND why my network times out

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YEAH - this is one weird DNS situation -
I'd like to find out what eventually turns out to be the problem with the  
DNS,
but this discussion is all over the map with various tangents regarding the  
orig problem.




Re: Frustrated that I don't UNDERSTAND why my network times out

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Re: Frustrated that I don't UNDERSTAND why my network times out

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Reading all I can of this thread (maybe not all because off my newsserver is  
not 100% reliable) I followed the diving into the routing and the protocol.  
AFAIS one cause has been overlooked so far: An intermittend hardware error.  
To me all results so far point in that direction. Suspect is all hardware  
between your computer and WISP. Shortest way to find out is exchanging all  
parts of it one at a time, including cables and power supplies. The logic  
behind it looks like obvious to me. All that equipment is similar to that of  
your neighbours but the latter has no problem. Your computer has no problem  
when using it too. So your equipment itself or the place or way it has been  
installed may cause that peculiar problem.

petrus bitbyter  



Re: Frustrated that I don't UNDERSTAND why my network times out
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It is hard for me to see how a hardware error could cause troubles with
ONLY centos.org. Remember that he says that he can  browse almost all
other web sites, even during the months that he cannot browse
centos.org. It is really really hard to imagine some hardware error that
would be that selective in its application, and furthermore one that
allowed the packets to reach the penultimate link on a long chain and
then fail on that final link.  

He has certainly been aware of your possibility, but has no idea how
that could explain the symptoms. Perhaps you could explain how, even in
the wildest of scenarios, this could explain his symptoms.  
And if it does, how he could figure our WHAT is wrong.  



Re: Frustrated that I don't UNDERSTAND why my network times out

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This reminds me of a problem I encountered with a system using a
RTL8111/8168B PCI Express Gigabit Ethernet controller.

Every once in a while, it would stop connecting to some sites, while
still working for other sites, and I could still use ssh to access
the system.

My nephew suggested rebooting the system. I explained, this was a
linux system, and wouldn't make any difference. After arguing a bit,
I rebooted it to show him, it wouldn't matter. To my surprise, it did
clear the problem.

That system is using a 50ft cable to connect to the router. My current
guess, is that some packet is getting mangled, some of the time, and
when it does, the only way to clear the problem, is to reset the pci
device, by rebooting the system.

Restarting the network is not enough. The system has to actually be
rebooted.  I suggested changing the wiring, and moving the router
so a shorter cable could be used, but the owner has chosen to just
reboot the system, whenever this happens, typically about every
other week.  This has been going on for a couple of years now, with
multiple kernel updates during that time, and no change in behaviour.

So there are cases where a hardware problem will affect some sites,
but not others.  Without disassembling the firmware, I have no
idea what the nic is doing, so I can only confirm the observed
results.

Regards, Dave Hodgins

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Re: Frustrated that I don't UNDERSTAND why my network times out

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Well, I agree. It's very hard see how it may happen. Nevertheless, the  
impossible never happens and hard to see is not impossible. In a situation  
like this I'd want to rule out the possibillity that the error is caused by  
my own equipment somehow. It's not only the pure hardware I think about. I  
consider the firmware a part of the hardware in this equipment. I have some  
experience maintaining computer equipment and I several times saw  
unexplainable errors disapear by exchanging parts or equipment that seem to  
have nothing to do with it.

*If* the cause of the problem has been located in this part of the path,  
there's a question left that may be next to impossible to answer: How does  
it happen? As the OP mentioned that's the most frustrating part of the  
problem.

petrus bitbyter  



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