[vox-tech] Internet Connectivity Weirdness

Richard S. Crawford rscrawford at mossroot.com
Mon Mar 12 10:44:28 PDT 2007


On Monday 12 March 2007 09:24:52 am Jeff Newmiller wrote:
> Richard S. Crawford wrote:
> > On Monday 12 March 2007 02:01:59 am Jeff Newmiller wrote:
> >>Richard S. Crawford wrote:
> >>>On Sunday 11 March 2007 09:39:29 pm Jeff Newmiller wrote:
> >>>>Richard S. Crawford wrote:
> >>>>>Over the past few days, I've been unable to reach my work website,
> >>>>>http://www.extensiondlc.net, from home.  I can reach just about every
> >>>>>other website in the world just fine; it's just that one (and its
> >>>>>various subdomains) that are causing the problems.  Furthermore, I can
> >>>>>reach the host, http://whsecure.net, just fine, but no subdomains.
> >>>>>This problem is only happening at home.
> >>>>>
> >>>>>When I try traceroute from any of the computers on my network, I get
> >>>>>this:
> >>>>>
> >>>>>richard at seamus:~
> >>>>>$ traceroute extensiondlc.net
> >>>>>traceroute to extensiondlc.net (66.232.56.196), 30 hops max, 40 byte
> >>>>>packets 1 * * *
> >>>>>2 * * *
> >>>>>3 * * *
> >>>>>4 * * *
> >>>>>...
> >>>>>30 * * *
> >>>>>
> >>>>>I get the same output no matter which site I try to traceroute to.
> >>>>>
> >>>>>In my experience, if I get timeouts at every instance in a traceroute,
> >>>>>it means my connection is down; yet, as I mentioned, I can get to just
> >>>>>about everywhere on the web except for that one domain just fine.
> >>>>>
> >>>>>I have already contacted my DSL provider, who insisted (naturally)
> >>>>> that nothing was wrong, and that they could not escalate my call.
> >>>>>
> >>>>>Can anyone offer some insight?\
> >>>>
> >>>>What is the output of
> >>>>
> >>>>  netstat -nr
> >>>>
> >>>>and
> >>>>
> >>>>  ip link
> >>>>
> >>>>
> >>>>from your home machines? Also, what is doing the routing for your
> >>>>
> >>>>home network? One of your linux boxes, or a commercial router?
> >>>
> >>>richard at seamus:~
> >>>$ netstat -nr
> >>>Kernel IP routing table
> >>>Destination     Gateway         Genmask         Flags   MSS Window  irtt
> >>>Iface 192.168.1.0     0.0.0.0         255.255.255.0   U         0 0
> >>>   0 eth0 0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0
> >>>       0 eth0
> >>>
> >>>richard at seamus:~
> >>>$ ip link
> >>>1: lo: <LOOPBACK,UP,10000> mtu 16436 qdisc noqueue
> >>>    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
> >>>2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen
> >>>1000 link/ether 00:30:bd:b3:f9:2f brd ff:ff:ff:ff:ff:ff
> >>>3: sit0: <NOARP> mtu 1480 qdisc noop
> >>>    link/sit 0.0.0.0 brd 0.0.0.0
> >>>
> >>>
> >>>I've got a Linksys router doing my routing for me.  :)
> >>
> >>The fact that the traceroute fails at the Linksys is wierd.
> >>If it failed outside your network, I could see the problem being
> >>an ISP router issue... but you can't even get a response from
> >>your own router.
> >>
> >>I was hoping an explanation might be found in a dead route to a vpn,
> >>but your response above indicates no dead routes on your computer.
> >>
> >>It is generally best to troubleshoot connectivity problems with
> >>IP numbers first... then when all that works, use DNS names to
> >>check out your DNS resolution.  Does traceroute work for other
> >>public IP addresses?
> >
> > Nope, it fails with all public IP addresses.
> >
> > If this were a router issue, though, wouldn't I be unable to get out at
> > all?
>
> No... it sounds like something is blocking the traceroute packets, and
> I am betting on your Linksys. Note that on windows, tracert uses ICMP
> packets, and on *nix uses UDP packets unless you use the "-I" option. [1]
> Since http connections use TCP packets, you probably have two different
> problems... trying out "-I" and looking through your Linksys configuration
> should turn up the problem.
>
> [1]
> http://joesbitbucket.blogspot.com/2006/10/linux-traceroute-vs-windows-trace
>rt.html

$traceroute -I www.extensiondlc.net gave me exactly the same output: * * *, 
etc.  I went ahead and replaced the router, and while I still can't reach the 
domain in question, at least now I know my router isn't to blame, unless 
something *really* weird is happening on my network.  Here's the newest 
traceroute:

richard at seamus:~
$ traceroute www.extensiondlc.net
traceroute to www.extensiondlc.net (66.232.56.196), 30 hops max, 40 byte 
packets
 1  192.168.1.1 (192.168.1.1)  0.344 ms  0.566 ms  0.275 ms
 2  adsl-63-207-85-254.dsl.scrm01.pacbell.net (63.207.85.254)  8.614 ms  8.041 
ms  7.606 ms
 3  dist2-vlan50.scrm01.pbi.net (64.171.152.67)  7.721 ms  7.329 ms  7.512 ms
 4  151.164.93.214 (151.164.93.214)  7.670 ms  8.414 ms  7.937 ms
 5  bb1-p13-3.crsfca.sbcglobal.net (151.164.43.233)  11.351 ms  12.441 ms  
12.935 ms
 6  ex1-p3-0.eqsjca.sbcglobal.net (151.164.41.101)  15.630 ms  14.359 ms  
14.368 ms
 7  ge3-17-1000M.ar2.SJC2.gblx.net (64.212.107.29)  20.968 ms  20.909 ms  
22.395 ms
 8  te1-1-10G.ar1.MIA2.gblx.net (67.17.108.62)  98.720 ms  98.969 ms  99.234 
ms
 9  INTERNAP.Tengigabitethernet2-2.ar1.MIA2.gblx.net (64.212.16.166)  98.212 
ms  78.993 ms  78.186 ms
10  border5.pc2.bbnet2.mia003.pnap.net (69.25.0.77)  170.763 ms  171.136 ms  
207.161 ms
11  webhosting-9.border5.mia003.pnap.net (216.52.162.66)  78.639 ms  79.149 ms  
78.487 ms
12  * * *
13  * * *
14  * * * 
etc.

The trick now is convincing the folks at Webhosting.net that the problem is 
closer to them than it is to me.




-- 
Richard S. Crawford (http://www.mossroot.com)
Editor In Chief, Daikaijuzine (http://www.daikaijuzine.com)
AIM: Buffalo2K / GTalk: underpope at gmail.com
"You can't trust your judgement when your imagination is out of focus."
		(Mark Twain)


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