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Re: [vox-tech] Internet Connectivity Weirdness
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Re: [vox-tech] Internet Connectivity Weirdness



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@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@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@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-tracert.html

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