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I have several devices on the network. Only one with a problem is this Ubuntu 12.04 machine. Its not a big problem and it is infrequent. So far, I have not noticed a particular cause/event.

At some point, I'll have no Internet connection. LAN is fine. I can SSH to the machine (I only have SSH access. Its headless). It can ping other LAN devices but no external devices. All other devices can ping it, and they can also ping external no problem.

Rebooting fixes (until the next time).

Its not the firewall... shut it off = no resolution.

I'm not really sure where to begin with diagnosing.

If I can't "fix" the problem... I'd settle for a command that can resolve without rebooting. Can I "refresh" the Internet connection?

Oh... this is a wired connection (Realtek GbE LAN chip).

edit: OK, happened again. Here is the output from "ip route show"

default via 10.1.0.5 dev tun0  proto static
10.1.0.1 via 10.1.0.5 dev tun0  proto static
10.1.0.5 dev tun0  proto kernel  scope link  src 10.1.0.6
169.254.0.0/16 dev eth0  scope link  metric 1000
174.127.121.246 via 192.168.1.1 dev eth0  proto static
192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.103  metric 1

edit: Output from "traceroute 8.8.8.8"

traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
 1  10.1.0.1 (10.1.0.1)  57.858 ms  57.848 ms  57.850 ms
 2  174.127.120.1.static.midphase.com (174.127.120.1)  57.873 ms  58.141 ms  58.152 ms
 3  ge-0-0-12.ar1.ord6.us.nlayer.net (69.31.110.85)  61.897 ms  61.913 ms  61.917 ms
 4  ae5-60g.cr2.ord1.us.nlayer.net (69.31.110.253)  58.123 ms ae5-60g.cr1.ord1.us.nlayer.net (69.31.110.249)  58.264 ms  61.899 ms
 5  ae1-30g.ar1.ord1.us.nlayer.net (69.31.111.134)  67.632 ms ae2-30g.ar1.ord1.us.nlayer.net (69.31.111.138)  67.634 ms  67.586 ms
 6  TenGigE0-0-1-0.GW5.CHI13.ALTER.NET (63.84.100.185)  64.629 ms  56.640 ms  56.632 ms
 7  0.xe-11-3-0.GW10.IAD8.ALTER.NET (152.63.35.237)  79.803 ms  80.161 ms  80.118 ms
 8  google-gw.customer.alter.net (152.179.50.50)  81.249 ms  85.203 ms  85.715 ms
 9  * 209.85.252.46 (209.85.252.46)  95.163 ms 209.85.252.80 (209.85.252.80)  85.975 ms
10  72.14.236.146 (72.14.236.146)  85.989 ms  86.221 ms  85.982 ms
11  72.14.235.12 (72.14.235.12)  93.830 ms 66.249.95.229 (66.249.95.229)  94.196 ms 66.249.95.231 (66.249.95.231)  93.752 ms
12  72.14.234.53 (72.14.234.53)  94.114 ms 72.14.234.55 (72.14.234.55)  90.566 ms 72.14.234.65 (72.14.234.65)  89.864 ms
13  * * *
14  google-public-dns-a.google.com (8.8.8.8)  89.826 ms  89.831 ms  90.489 ms

closed as off-topic by user117103, Alvar, blade19899, Braiam, Andrea Corbellini Jan 3 '14 at 18:01

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This describes a problem that can't be reproduced that seemingly went away on its own or was only relevant to a very specific period of time. It's off-topic as it's unlikely to help future readers." – guntbert, Alvar, blade19899, Braiam, Andrea Corbellini
If this question can be reworded to fit the rules in the help center, please edit the question.

  • It just happened again... so I'm still looking for answers :( – bcsteeve Dec 6 '13 at 22:03
  • You said you can ssh into the machine all the time - that might be a clue to a routing problem - when it happens look at (and edit your question to show us) the output of ip route show. – guntbert Dec 6 '13 at 23:14
  • I appreciate that, thanks. Next time it happens, I'll get that output and update my question. – bcsteeve Dec 7 '13 at 3:11
  • Output from ip route show added to question. Does that tell you anything at all? I'm guessing not... after reboot, which fixes the issue, the output of that same command is identical. – bcsteeve Dec 11 '13 at 4:07
  • 1
    It does indeed show an anomaly - you may have overlooked that when comparing to the situation after a reboot. The 1st line (default...) should probably not point to your VPN but to a router in the 192.168.1.0/24 network. If my suspicion is correct we will still have to find out what causes that. – guntbert Dec 11 '13 at 17:03

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